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Not the Neck-tar of the Gods
ANSWER
The correct answer is cutaneous sinus tract of odontogenic origin (choice “d”).
DISCUSSION
These uncommon lesions are known by several names, including odontogenic fistula. Invariably, they are misdiagnosed as an “infection” and treated with antibiotics, which only calm these lesions until they inevitably return to their pretreatment appearance. Though bacteria (mostly Peptostreptococcus—the anaerobe predominating in the mouth) are involved, this is not an infection as it usually manifests.
The underlying process of this condition is caused by a periapical abscess: as it grows in size and pressure, it enters into the mouth or fistulizes out through the buccal tissue, continuing until it penetrates the skin and begins to release its pustular contents. Eighty percent manifest on the submental or chin area, while 20% tunnel inwards toward the oral cavity.
They initially manifest as papules with a 2-to-3-mm surface that soon drain pus from a central sinus. As this continues, the epithelium responds to the chronic inflammation by forming a mass of pseudoepitheliomatous hyperplasia. Biopsy would reveal that the mass also shows signs of chronic inflammation. Ordinary bacterial culture often shows nothing because the predominant organism is an anaerobe. At most, one might see a polymicrobial result.
TREATMENT
For affected patients, a dentist can be considered for radiography of the area to confirm the location of the periapical abscess. Then the tooth is usually extracted, resulting in a cure. No further treatment of the sinus tract is necessary because it will essentially disappear over time. The tract does not require excision because it is lined with reactive granulation tissue and not epithelium (as is the case for many other fistular processes).
If the dental exam and radiograph fail to show the expected result, the other diagnoses—thyroglossal duct cyst, branchial cleft cyst, squamous cell carcinoma—would have to be considered.
ANSWER
The correct answer is cutaneous sinus tract of odontogenic origin (choice “d”).
DISCUSSION
These uncommon lesions are known by several names, including odontogenic fistula. Invariably, they are misdiagnosed as an “infection” and treated with antibiotics, which only calm these lesions until they inevitably return to their pretreatment appearance. Though bacteria (mostly Peptostreptococcus—the anaerobe predominating in the mouth) are involved, this is not an infection as it usually manifests.
The underlying process of this condition is caused by a periapical abscess: as it grows in size and pressure, it enters into the mouth or fistulizes out through the buccal tissue, continuing until it penetrates the skin and begins to release its pustular contents. Eighty percent manifest on the submental or chin area, while 20% tunnel inwards toward the oral cavity.
They initially manifest as papules with a 2-to-3-mm surface that soon drain pus from a central sinus. As this continues, the epithelium responds to the chronic inflammation by forming a mass of pseudoepitheliomatous hyperplasia. Biopsy would reveal that the mass also shows signs of chronic inflammation. Ordinary bacterial culture often shows nothing because the predominant organism is an anaerobe. At most, one might see a polymicrobial result.
TREATMENT
For affected patients, a dentist can be considered for radiography of the area to confirm the location of the periapical abscess. Then the tooth is usually extracted, resulting in a cure. No further treatment of the sinus tract is necessary because it will essentially disappear over time. The tract does not require excision because it is lined with reactive granulation tissue and not epithelium (as is the case for many other fistular processes).
If the dental exam and radiograph fail to show the expected result, the other diagnoses—thyroglossal duct cyst, branchial cleft cyst, squamous cell carcinoma—would have to be considered.
ANSWER
The correct answer is cutaneous sinus tract of odontogenic origin (choice “d”).
DISCUSSION
These uncommon lesions are known by several names, including odontogenic fistula. Invariably, they are misdiagnosed as an “infection” and treated with antibiotics, which only calm these lesions until they inevitably return to their pretreatment appearance. Though bacteria (mostly Peptostreptococcus—the anaerobe predominating in the mouth) are involved, this is not an infection as it usually manifests.
The underlying process of this condition is caused by a periapical abscess: as it grows in size and pressure, it enters into the mouth or fistulizes out through the buccal tissue, continuing until it penetrates the skin and begins to release its pustular contents. Eighty percent manifest on the submental or chin area, while 20% tunnel inwards toward the oral cavity.
They initially manifest as papules with a 2-to-3-mm surface that soon drain pus from a central sinus. As this continues, the epithelium responds to the chronic inflammation by forming a mass of pseudoepitheliomatous hyperplasia. Biopsy would reveal that the mass also shows signs of chronic inflammation. Ordinary bacterial culture often shows nothing because the predominant organism is an anaerobe. At most, one might see a polymicrobial result.
TREATMENT
For affected patients, a dentist can be considered for radiography of the area to confirm the location of the periapical abscess. Then the tooth is usually extracted, resulting in a cure. No further treatment of the sinus tract is necessary because it will essentially disappear over time. The tract does not require excision because it is lined with reactive granulation tissue and not epithelium (as is the case for many other fistular processes).
If the dental exam and radiograph fail to show the expected result, the other diagnoses—thyroglossal duct cyst, branchial cleft cyst, squamous cell carcinoma—would have to be considered.
For 4 years, the lesion on this 66-year-old woman’s chin has been growing slowly, causing little or no pain. However, a foul-smelling cloudy liquid drains from the site about once a week and—understandably—causes her considerable distress. Her primary care provider (PCP) regarded the problem as an infection and prescribed an antibiotic, which reduced the lesion’s size for a time. However, it soon grew again after the patient completed the treatment.
The patient denies any other serious health conditions such as diabetes or immunosuppression. She states she never had an injury to this area. Concerned about the possibility of skin cancer, the PCP refers the patient to dermatology.
Physical exam reveals a patient in no particular distress, afebrile, and oriented in all 3 spheres. She is cooperative with the history and exam. Her husband, who has accompanied her, helps to corroborate her answers.
The lesion is striking both in size (2.8 cm) and mixed morphology. A deeply retracted 1.5-cm dimple is located on the right lower chin/submental interface, situated evenly with the right lateral oral commissure. There is no erythema in this area or elsewhere in or around the lesion.
A fleshy, vermicular, 2 × 4–mm, soft, friable linear mass protrudes from the dimple, extending toward the submental region. Gentle pressure produces a small amount of pustular material issuing from the center of the retracted area. There are no other nodes in the region. There is little or no evidence of past overexposure to ultraviolet sources (dyschromia, weathering, actinic keratoses, or telangiectasias).
Lesion Has Been Giving Him an Earful
ANSWER
The correct answer is gouty tophus (choice “b”).
DISCUSSION
Gout is a defect of purine metabolism, usually caused by underexcretion of uric acid. Diet and heredity also play parts in gout’s development. Gouty tophi usually develop after years of hyperuricemia. As uric acid builds up in the bloodstream over time, it can then begin to be deposited into joints—most commonly the first metatarsal-phalangeal—as well as cartilage or even bones.
On further questioning, the patient recalled having been told on several occasions that his serum uric acid was elevated. In retrospect, his arthritis was most likely gouty in nature.
In terms of the differential, BCC (choice “a”) is common on helical rims, but it would not have contained the type of material found in this patient’s lesion. Also, it would not have waxed and waned as this lesion had done.
Epidermal cysts (choice “c”) can certainly come and go in prominence, but they are filled with a cheesy, pasty material—not the dry crystalline substance found in this lesion. Moreover, most epidermal cysts will have a small comedonal punctum over the center of the lesion. Dystrophic calcification (choice “d”) can mimic gouty tophi, but it is usually rough, firm, and fixed. It certainly would not be coming and going as it pleases.
TREATMENT
Surgical excision of the tophus was offered, but the patient was content with knowing the correct diagnosis. His PCP had previously explained therapeutic options—such as medication and dietary changes—that could address the overall problem. The patient elected to pursue treatment with his PCP.
ANSWER
The correct answer is gouty tophus (choice “b”).
DISCUSSION
Gout is a defect of purine metabolism, usually caused by underexcretion of uric acid. Diet and heredity also play parts in gout’s development. Gouty tophi usually develop after years of hyperuricemia. As uric acid builds up in the bloodstream over time, it can then begin to be deposited into joints—most commonly the first metatarsal-phalangeal—as well as cartilage or even bones.
On further questioning, the patient recalled having been told on several occasions that his serum uric acid was elevated. In retrospect, his arthritis was most likely gouty in nature.
In terms of the differential, BCC (choice “a”) is common on helical rims, but it would not have contained the type of material found in this patient’s lesion. Also, it would not have waxed and waned as this lesion had done.
Epidermal cysts (choice “c”) can certainly come and go in prominence, but they are filled with a cheesy, pasty material—not the dry crystalline substance found in this lesion. Moreover, most epidermal cysts will have a small comedonal punctum over the center of the lesion. Dystrophic calcification (choice “d”) can mimic gouty tophi, but it is usually rough, firm, and fixed. It certainly would not be coming and going as it pleases.
TREATMENT
Surgical excision of the tophus was offered, but the patient was content with knowing the correct diagnosis. His PCP had previously explained therapeutic options—such as medication and dietary changes—that could address the overall problem. The patient elected to pursue treatment with his PCP.
ANSWER
The correct answer is gouty tophus (choice “b”).
DISCUSSION
Gout is a defect of purine metabolism, usually caused by underexcretion of uric acid. Diet and heredity also play parts in gout’s development. Gouty tophi usually develop after years of hyperuricemia. As uric acid builds up in the bloodstream over time, it can then begin to be deposited into joints—most commonly the first metatarsal-phalangeal—as well as cartilage or even bones.
On further questioning, the patient recalled having been told on several occasions that his serum uric acid was elevated. In retrospect, his arthritis was most likely gouty in nature.
In terms of the differential, BCC (choice “a”) is common on helical rims, but it would not have contained the type of material found in this patient’s lesion. Also, it would not have waxed and waned as this lesion had done.
Epidermal cysts (choice “c”) can certainly come and go in prominence, but they are filled with a cheesy, pasty material—not the dry crystalline substance found in this lesion. Moreover, most epidermal cysts will have a small comedonal punctum over the center of the lesion. Dystrophic calcification (choice “d”) can mimic gouty tophi, but it is usually rough, firm, and fixed. It certainly would not be coming and going as it pleases.
TREATMENT
Surgical excision of the tophus was offered, but the patient was content with knowing the correct diagnosis. His PCP had previously explained therapeutic options—such as medication and dietary changes—that could address the overall problem. The patient elected to pursue treatment with his PCP.
Over the years, the lesion on this 49-year-old man’s right ear has waxed and waned in prominence. Although it never causes pain, its unrelenting existence coupled with a history of basal cell carcinoma (BCC) on his face has caused him to worry. He has had no other lesions and is in otherwise good health, except for occasional bouts of arthritis, for which he takes ibuprofen, with good results.
While his family had suggested that the lesion could be a cyst, his primary care provider (PCP) disagreed and referred him to dermatology.
A 5-mm firm papule is located at the right helical crest. The lesion is skin-colored, with no redness, and nontender on palpation, although it is moderately firm and mobile. No punctum is noted.
The surrounding skin has no signs of sun damage, although the patient is quite fair. As a young man, he had far too much sun exposure, burning easily and tanning only with difficulty.
After consultation with the patient, the decision is made to incise the lesion using a #11 blade to examine its contents. The incision reveals a dry crystalline substance, which is easily cleared with brief curettage. This effectively leads to a flattening of the lesion.
Digits in Distress
ANSWER
The correct answer is acrodermatitis of Hallopeau (choice “c”).
DISCUSSION
Acrodermatitis of Hallopeau (ADH), a rare form of pustular psoriasis, affects the distal digits with changes typified by this patient’s case. It is notoriously difficult to treat, although the advent of the “biologic age” appears to offer a quantum leap in terms of effective treatment alternatives.
Prompt referral to dermatology is needed for ADH to be readily diagnosed and treated. Because ADH is both rare and obscure, it’s not surprising that so many patients suffer for years due to an incorrect diagnosis. And even when correctly diagnosed, treatment is far from satisfactory. For example, methotrexate is commonly used for psoriasis vulgaris but rarely improves ADH—nor do topical steroids or vitamin D–derived topicals.
The 3 other items in the differential would not explain the patient’s condition: (1) Except in cases of immunosuppression, we would not expect Candida (choice “a”) or any other yeast infection to manifest in this manner. (2) Atypical mycobacteria (choice “b”)—such as Mycobacterium marinum—can cause skin infections, but not in a chronically relapsing manner. Moreover, this patient was given minocycline, which would have quickly cleared or at least improved his condition. (3) Pityriasis rubra pilaris (choice “d”) is an unusual papulosquamous disease that can affect nails, but its manifestation would not be as limited as this patient’s was.
TREATMENT
Because the patient’s symptoms are sometimes severe enough to interfere with almost all daily activities, he is clearly in need of prompt treatment. In more severe cases, a short course of cyclosporine followed by a biologic can be an option. For this patient, adalimumab was used. Although it is too early to tell, we expect him to be much improved within a few months.
ANSWER
The correct answer is acrodermatitis of Hallopeau (choice “c”).
DISCUSSION
Acrodermatitis of Hallopeau (ADH), a rare form of pustular psoriasis, affects the distal digits with changes typified by this patient’s case. It is notoriously difficult to treat, although the advent of the “biologic age” appears to offer a quantum leap in terms of effective treatment alternatives.
Prompt referral to dermatology is needed for ADH to be readily diagnosed and treated. Because ADH is both rare and obscure, it’s not surprising that so many patients suffer for years due to an incorrect diagnosis. And even when correctly diagnosed, treatment is far from satisfactory. For example, methotrexate is commonly used for psoriasis vulgaris but rarely improves ADH—nor do topical steroids or vitamin D–derived topicals.
The 3 other items in the differential would not explain the patient’s condition: (1) Except in cases of immunosuppression, we would not expect Candida (choice “a”) or any other yeast infection to manifest in this manner. (2) Atypical mycobacteria (choice “b”)—such as Mycobacterium marinum—can cause skin infections, but not in a chronically relapsing manner. Moreover, this patient was given minocycline, which would have quickly cleared or at least improved his condition. (3) Pityriasis rubra pilaris (choice “d”) is an unusual papulosquamous disease that can affect nails, but its manifestation would not be as limited as this patient’s was.
TREATMENT
Because the patient’s symptoms are sometimes severe enough to interfere with almost all daily activities, he is clearly in need of prompt treatment. In more severe cases, a short course of cyclosporine followed by a biologic can be an option. For this patient, adalimumab was used. Although it is too early to tell, we expect him to be much improved within a few months.
ANSWER
The correct answer is acrodermatitis of Hallopeau (choice “c”).
DISCUSSION
Acrodermatitis of Hallopeau (ADH), a rare form of pustular psoriasis, affects the distal digits with changes typified by this patient’s case. It is notoriously difficult to treat, although the advent of the “biologic age” appears to offer a quantum leap in terms of effective treatment alternatives.
Prompt referral to dermatology is needed for ADH to be readily diagnosed and treated. Because ADH is both rare and obscure, it’s not surprising that so many patients suffer for years due to an incorrect diagnosis. And even when correctly diagnosed, treatment is far from satisfactory. For example, methotrexate is commonly used for psoriasis vulgaris but rarely improves ADH—nor do topical steroids or vitamin D–derived topicals.
The 3 other items in the differential would not explain the patient’s condition: (1) Except in cases of immunosuppression, we would not expect Candida (choice “a”) or any other yeast infection to manifest in this manner. (2) Atypical mycobacteria (choice “b”)—such as Mycobacterium marinum—can cause skin infections, but not in a chronically relapsing manner. Moreover, this patient was given minocycline, which would have quickly cleared or at least improved his condition. (3) Pityriasis rubra pilaris (choice “d”) is an unusual papulosquamous disease that can affect nails, but its manifestation would not be as limited as this patient’s was.
TREATMENT
Because the patient’s symptoms are sometimes severe enough to interfere with almost all daily activities, he is clearly in need of prompt treatment. In more severe cases, a short course of cyclosporine followed by a biologic can be an option. For this patient, adalimumab was used. Although it is too early to tell, we expect him to be much improved within a few months.
For years, a 29-year-old man has been troubled by persistent painful outbreaks on his right thumb and forefinger and left great toe. The condition sometimes prevents him from engaging in daily activities. Several health care providers—none a dermatology specialist—attempted to treat him with topical and oral antifungals (clotrimazole and terbinafine), topical steroids (triamcinolone and clobetasol), and oral antibiotics (including minocycline)—none of which had an impact.
His latest provider, a podiatrist, was sure the problem was fungal in origin and prescribed another course of antifungal treatment. When this failed to produce a benefit, the podiatrist conceded that he was at a loss and referred the patient to dermatology.
On physical exam, the 3 affected digits show similar characteristics: the skin is covered by dense, tenacious scaling on a dark red base. Small pustules are noted on these areas in addition to marked dystrophy of the adjacent nails. Bacterial and fungal cultures of the pustular fluid show no growth.
The rest of the patient’s skin—elbows, oral mucosa, knees, and scalp—show no noteworthy changes. He has no other skin problems. There is no family history of psoriasis or other skin conditions.
Baby’s Got Back Rash
ANSWER
The correct answer is psoriasis vulgaris (choice “a”).
DISCUSSION
At least 30% of patients with psoriasis have a family history of the disease—a meaningful clue in developing a differential. Besides asking about the history, always look for corroborating signs in areas where the disease is commonly seen (eg, the fingernails). In this case, further corroboration was provided by the history of illness at the time of the rash’s onset; what was initially strep-driven guttate psoriasis morphed into full-blown psoriasis vulgaris.
The heavy scales, with their salmon-pink base, tipped the scales in favor of psoriasis as the diagnosis. The pinpoint bleeding (known as the Auspitz sign), although not pathognomic for psoriasis, is certainly suggestive of it.
In adults, these findings would probably have been sufficient to settle on psoriasis. But before labeling a young child with a serious, lifelong diagnosis, it was necessary to be sure. For one thing, advanced psoriasis is very unusual in children as young as this patient, and for another, treatment would likely be problematic. Fortunately for clarity’s sake, the biopsy was consistent with psoriasis and inconsistent with the other items in the differential.
TREATMENT
The patient was prescribed a topical steroid cream to apply every other day, alternating with vitamin D–derived ointment. In addition, he was advised to increase his exposure to natural sunlight. Phototherapy with narrow-band ultraviolet light B would be a superior option, but his family lives too far from the clinic to make 3 roundtrips per week for such treatment.
If these measures fail, a biologic agent may be appropriate. Unfortunately, the patient’s insurance carrier requires the failure of several other modalities before it will approve use of such therapy.
ANSWER
The correct answer is psoriasis vulgaris (choice “a”).
DISCUSSION
At least 30% of patients with psoriasis have a family history of the disease—a meaningful clue in developing a differential. Besides asking about the history, always look for corroborating signs in areas where the disease is commonly seen (eg, the fingernails). In this case, further corroboration was provided by the history of illness at the time of the rash’s onset; what was initially strep-driven guttate psoriasis morphed into full-blown psoriasis vulgaris.
The heavy scales, with their salmon-pink base, tipped the scales in favor of psoriasis as the diagnosis. The pinpoint bleeding (known as the Auspitz sign), although not pathognomic for psoriasis, is certainly suggestive of it.
In adults, these findings would probably have been sufficient to settle on psoriasis. But before labeling a young child with a serious, lifelong diagnosis, it was necessary to be sure. For one thing, advanced psoriasis is very unusual in children as young as this patient, and for another, treatment would likely be problematic. Fortunately for clarity’s sake, the biopsy was consistent with psoriasis and inconsistent with the other items in the differential.
TREATMENT
The patient was prescribed a topical steroid cream to apply every other day, alternating with vitamin D–derived ointment. In addition, he was advised to increase his exposure to natural sunlight. Phototherapy with narrow-band ultraviolet light B would be a superior option, but his family lives too far from the clinic to make 3 roundtrips per week for such treatment.
If these measures fail, a biologic agent may be appropriate. Unfortunately, the patient’s insurance carrier requires the failure of several other modalities before it will approve use of such therapy.
ANSWER
The correct answer is psoriasis vulgaris (choice “a”).
DISCUSSION
At least 30% of patients with psoriasis have a family history of the disease—a meaningful clue in developing a differential. Besides asking about the history, always look for corroborating signs in areas where the disease is commonly seen (eg, the fingernails). In this case, further corroboration was provided by the history of illness at the time of the rash’s onset; what was initially strep-driven guttate psoriasis morphed into full-blown psoriasis vulgaris.
The heavy scales, with their salmon-pink base, tipped the scales in favor of psoriasis as the diagnosis. The pinpoint bleeding (known as the Auspitz sign), although not pathognomic for psoriasis, is certainly suggestive of it.
In adults, these findings would probably have been sufficient to settle on psoriasis. But before labeling a young child with a serious, lifelong diagnosis, it was necessary to be sure. For one thing, advanced psoriasis is very unusual in children as young as this patient, and for another, treatment would likely be problematic. Fortunately for clarity’s sake, the biopsy was consistent with psoriasis and inconsistent with the other items in the differential.
TREATMENT
The patient was prescribed a topical steroid cream to apply every other day, alternating with vitamin D–derived ointment. In addition, he was advised to increase his exposure to natural sunlight. Phototherapy with narrow-band ultraviolet light B would be a superior option, but his family lives too far from the clinic to make 3 roundtrips per week for such treatment.
If these measures fail, a biologic agent may be appropriate. Unfortunately, the patient’s insurance carrier requires the failure of several other modalities before it will approve use of such therapy.
Several months ago, a rash of numerous small, red, scaly papules and patches manifested on this 3-year-old boy’s back and shoulders. At the time, he had been ill for about a week, and his primary care provider diagnosed chickenpox—even though the child had been immunized.
Although the patient’s health soon improved, the appearance of the rash worsened. Treatment with various products—including calamine lotion, OTC tolnaftate and miconazole, and a 2-week course of oral antibiotics—was of no help. Finally, the patient was referred to dermatology.
Family history is positive for psoriasis. However, the parents are quick to note that the boy’s rash appears far different from that of affected family members, and previous providers have dismissed this diagnosis from the differential. There is no family or personal history of atopy.
Examination reveals a dense papulosquamous rash mainly confined to the child’s back and posterior shoulders (the area over the scapula). No other areas are similarly affected, but 1 fingernail is mildly pitted.
A #10 blade lifts the edge of one of the scales gently (and painlessly) until there is pinpoint bleeding from 2 tiny foci. A 5-mm full-thickness punch biopsy with primary closure shows marked parakeratosis, collections of neutrophils on the crests of dermal papillae, and fusing of rete ridges, which effectively obscure the normal wave-like pattern of the dermoepidermal junction.
Chin There, Done That—Now What?
ANSWER
The correct answer is to perform a 3-mm punch biopsy (choice “a”).
DISCUSSION
When the history and physical exam fail to point to a clear diagnosis, skin biopsy can answer a very basic question: What is the pathophysiologic process associated with the lesions? The information thus obtained doesn’t always produce a blinking neon sign of a diagnosis, but at a minimum, it can rule out a great number of things, such as cancer or infection.
More often, the types of cells seen, and the patterns in which they are arranged, tell us a great deal. In this case, accumulations of monocytes, macrophages, and activated T-lymphocytes were arranged in circular patterns, but there was no evidence of necrosis (caseation), which can be seen in tubercular granulomas. Stains performed to identify mycobacterial organisms were negative. These findings established the diagnosis of cutaneous sarcoidosis, a granulomatous disease thought to represent a reaction to an unknown antigen (eg, a microorganism) or environmental substance. It is far more common in those with darker skin types.
Although this patient’s disease was confined to the skin, sarcoidosis can affect virtually any other organ in the body—in particular, the lungs, kidneys, liver, nervous system, or even the eyes. For this reason, patients with sarcoidosis are usually referred to pulmonology for a workup intended to rule out systemic involvement and to other specialists as symptoms dictate.
Many cases of sarcoidosis remit on their own, without treatment. When treatment is initiated, the 2 most commonly used medications are systemic glucocorticoids and/or methotrexate. Both drugs have been associated with serious adverse effects and should only be prescribed by experienced providers.
This combination was prescribed for the case patient, who obtained rapid relief. Blood work (complete blood count, comprehensive metabolic panel) was within normal limits prior to and during treatment, and the pulmonologist pronounced her free of lung involvement.
ANSWER
The correct answer is to perform a 3-mm punch biopsy (choice “a”).
DISCUSSION
When the history and physical exam fail to point to a clear diagnosis, skin biopsy can answer a very basic question: What is the pathophysiologic process associated with the lesions? The information thus obtained doesn’t always produce a blinking neon sign of a diagnosis, but at a minimum, it can rule out a great number of things, such as cancer or infection.
More often, the types of cells seen, and the patterns in which they are arranged, tell us a great deal. In this case, accumulations of monocytes, macrophages, and activated T-lymphocytes were arranged in circular patterns, but there was no evidence of necrosis (caseation), which can be seen in tubercular granulomas. Stains performed to identify mycobacterial organisms were negative. These findings established the diagnosis of cutaneous sarcoidosis, a granulomatous disease thought to represent a reaction to an unknown antigen (eg, a microorganism) or environmental substance. It is far more common in those with darker skin types.
Although this patient’s disease was confined to the skin, sarcoidosis can affect virtually any other organ in the body—in particular, the lungs, kidneys, liver, nervous system, or even the eyes. For this reason, patients with sarcoidosis are usually referred to pulmonology for a workup intended to rule out systemic involvement and to other specialists as symptoms dictate.
Many cases of sarcoidosis remit on their own, without treatment. When treatment is initiated, the 2 most commonly used medications are systemic glucocorticoids and/or methotrexate. Both drugs have been associated with serious adverse effects and should only be prescribed by experienced providers.
This combination was prescribed for the case patient, who obtained rapid relief. Blood work (complete blood count, comprehensive metabolic panel) was within normal limits prior to and during treatment, and the pulmonologist pronounced her free of lung involvement.
ANSWER
The correct answer is to perform a 3-mm punch biopsy (choice “a”).
DISCUSSION
When the history and physical exam fail to point to a clear diagnosis, skin biopsy can answer a very basic question: What is the pathophysiologic process associated with the lesions? The information thus obtained doesn’t always produce a blinking neon sign of a diagnosis, but at a minimum, it can rule out a great number of things, such as cancer or infection.
More often, the types of cells seen, and the patterns in which they are arranged, tell us a great deal. In this case, accumulations of monocytes, macrophages, and activated T-lymphocytes were arranged in circular patterns, but there was no evidence of necrosis (caseation), which can be seen in tubercular granulomas. Stains performed to identify mycobacterial organisms were negative. These findings established the diagnosis of cutaneous sarcoidosis, a granulomatous disease thought to represent a reaction to an unknown antigen (eg, a microorganism) or environmental substance. It is far more common in those with darker skin types.
Although this patient’s disease was confined to the skin, sarcoidosis can affect virtually any other organ in the body—in particular, the lungs, kidneys, liver, nervous system, or even the eyes. For this reason, patients with sarcoidosis are usually referred to pulmonology for a workup intended to rule out systemic involvement and to other specialists as symptoms dictate.
Many cases of sarcoidosis remit on their own, without treatment. When treatment is initiated, the 2 most commonly used medications are systemic glucocorticoids and/or methotrexate. Both drugs have been associated with serious adverse effects and should only be prescribed by experienced providers.
This combination was prescribed for the case patient, who obtained rapid relief. Blood work (complete blood count, comprehensive metabolic panel) was within normal limits prior to and during treatment, and the pulmonologist pronounced her free of lung involvement.
A 51-year-old woman is referred to dermatology for evaluation of a facial rash that has been present, on and off, for years. It usually affects her right chin and perioral area but occasionally manifests with smaller yet similar lesions elsewhere on the face. The lesions are slightly itchy, but the patient’s main concern is their impact on her appearance.
She has consulted several primary care providers over the years, all of whom initially diagnosed and treated for acne—to no avail. This was typically followed by a recommendation to try an OTC topical product, such as an antifungal (tolnaftate and clotrimazole), hydrocortisone 1%, or triple-antibiotic cream—again, without improvement. At no point was a biopsy suggested.
Examination reveals a dense cluster of papules covering a 5×4-cm section of the right chin and perioral area. Although the lesions appear vesicular, they are in fact solid but soft, shiny, and confluent. The papules are about the same color as her type IV skin. There are no comedones or pustules.
No adenopathy is detected in the region. There is no involvement of the adjacent oral mucosal surfaces.
The patient’s skin elsewhere is unremarkable, and in general, she appears to be in good health (certainly in no distress). She claims to be healthy otherwise, with no fever, malaise, joint pain, fatigue, or shortness of breath. No one else in her household is similarly affected.
Could This Lesion Be Deadly?
ANSWER
The correct diagnosis is blue nevus (BN; choice “d”).
Some BNs can mimic melanomas (choice “a”), and vice versa. These cases often have to be sent to consultants, and sometimes even they can’t agree. For this reason, there is a low threshold for removal if there’s any question of change or family history of melanoma—which were missing in this case.
Kaposi sarcoma (KS; choice “b”) is a type of cancer caused by human herpesvirus-8 that affects the inner lining of blood vessels and manifests with dark macules or nodules. But outside the context of HIV/AIDS, KS is quite rare.
This lesion could have been an angioma (choice “c”), but its history and dark blue color made that diagnosis unlikely. In younger patients, angiomas are typically bright red. Only later, in the sixth and seventh decades of life, do they take on a dark appearance.
DISCUSSION
BNs are benign melanocytic nevi that typically appear on the trunk or upper extremities during the second or third decade of life. There are several varieties, the most common of which (and the type seen in this case) is Jadassohn-Tieche. The steel-blue color and planar surface of this patient’s lesion are typical.
Histologically, BNs are composed mostly of pigmented melanocytes that congregate deep in the dermis (unlike normal melanocytes, which typically line the dermo-epidermal junction). While these melanocytes are usually brown, they take on a bluish hue when they develop on a deeper level of skin—a phenomenon known as the Tyndall effect.
It can be challenging to differentiate a BN from a melanoma, even with a microscope. Sometimes the answer is to treat the lesion as though it were a melanoma by excising it with wide margins.
In this case, given the benign appearance and history, the decision was made to leave it alone unless it changes. Excision might have been a good option, but the patient’s type IV skin and the lesion’s location made scarring a likely possibility.
ANSWER
The correct diagnosis is blue nevus (BN; choice “d”).
Some BNs can mimic melanomas (choice “a”), and vice versa. These cases often have to be sent to consultants, and sometimes even they can’t agree. For this reason, there is a low threshold for removal if there’s any question of change or family history of melanoma—which were missing in this case.
Kaposi sarcoma (KS; choice “b”) is a type of cancer caused by human herpesvirus-8 that affects the inner lining of blood vessels and manifests with dark macules or nodules. But outside the context of HIV/AIDS, KS is quite rare.
This lesion could have been an angioma (choice “c”), but its history and dark blue color made that diagnosis unlikely. In younger patients, angiomas are typically bright red. Only later, in the sixth and seventh decades of life, do they take on a dark appearance.
DISCUSSION
BNs are benign melanocytic nevi that typically appear on the trunk or upper extremities during the second or third decade of life. There are several varieties, the most common of which (and the type seen in this case) is Jadassohn-Tieche. The steel-blue color and planar surface of this patient’s lesion are typical.
Histologically, BNs are composed mostly of pigmented melanocytes that congregate deep in the dermis (unlike normal melanocytes, which typically line the dermo-epidermal junction). While these melanocytes are usually brown, they take on a bluish hue when they develop on a deeper level of skin—a phenomenon known as the Tyndall effect.
It can be challenging to differentiate a BN from a melanoma, even with a microscope. Sometimes the answer is to treat the lesion as though it were a melanoma by excising it with wide margins.
In this case, given the benign appearance and history, the decision was made to leave it alone unless it changes. Excision might have been a good option, but the patient’s type IV skin and the lesion’s location made scarring a likely possibility.
ANSWER
The correct diagnosis is blue nevus (BN; choice “d”).
Some BNs can mimic melanomas (choice “a”), and vice versa. These cases often have to be sent to consultants, and sometimes even they can’t agree. For this reason, there is a low threshold for removal if there’s any question of change or family history of melanoma—which were missing in this case.
Kaposi sarcoma (KS; choice “b”) is a type of cancer caused by human herpesvirus-8 that affects the inner lining of blood vessels and manifests with dark macules or nodules. But outside the context of HIV/AIDS, KS is quite rare.
This lesion could have been an angioma (choice “c”), but its history and dark blue color made that diagnosis unlikely. In younger patients, angiomas are typically bright red. Only later, in the sixth and seventh decades of life, do they take on a dark appearance.
DISCUSSION
BNs are benign melanocytic nevi that typically appear on the trunk or upper extremities during the second or third decade of life. There are several varieties, the most common of which (and the type seen in this case) is Jadassohn-Tieche. The steel-blue color and planar surface of this patient’s lesion are typical.
Histologically, BNs are composed mostly of pigmented melanocytes that congregate deep in the dermis (unlike normal melanocytes, which typically line the dermo-epidermal junction). While these melanocytes are usually brown, they take on a bluish hue when they develop on a deeper level of skin—a phenomenon known as the Tyndall effect.
It can be challenging to differentiate a BN from a melanoma, even with a microscope. Sometimes the answer is to treat the lesion as though it were a melanoma by excising it with wide margins.
In this case, given the benign appearance and history, the decision was made to leave it alone unless it changes. Excision might have been a good option, but the patient’s type IV skin and the lesion’s location made scarring a likely possibility.
For years, this 24-year-old woman has had an asymptomatic lesion on her upper arm. Aside from growing a bit, as she has, it has remained basically unchanged.
The bluish black, intradermal, planar nodule is located on the lateral right deltoid. Barely palpable, the 7-mm lesion is neither tender nor particularly firm.
The patient is otherwise healthy. Her type IV skin shows little evidence of sun damage.
Can You Treat These Feet?
ANSWER
The item that does not belong is tinea corporis (ringworm; choice “c”). There are several reasons this presumed, “obvious” diagnosis does not belong: First, there was no known source (human or animal) from which the patient could have contracted such an infection. Second, what should have been adequate treatment for a fungal infection had no effect. And finally, cutaneous fungal infections almost always disrupt the outer layer of skin; the relevant signs (eg, scaling, vesiculation, follicular granulomas) were absent in this case.
The correct diagnosis is granuloma annulare (GA; choice “a”), an extremely common, benign condition that is often misdiagnosed and treated as fungal infection. Histologically, GA is characterized by palisading (row-like) collections of cells that group together to form granulomas.
Similar patterns can be seen with sarcoidosis (choice “b”) and cutaneous mycobacterial infection (choice “d”), but additional distinguishing histologic features must be sought to confirm those diagnoses.
DISCUSSION
Virtually every medical provider has fallen for this clinical canard, referring an alleged “fungal infection” to dermatology when it fails to respond to treatment. This case was archetypical of GA, a condition most commonly found on the feet of young women.
It manifests on the extensor surfaces of the extremities as brownish red, round-to-oval, intradermal plaques devoid of surface disruption. The borders of the lesions are often raised enough to produce an apparent valley (delling) in the center.
There is a rather wide spectrum of GA variants (eg, generalized, su
Many treatments have been used (including topical or intralesional steroids and liquid nitrogen), but none are particularly effective. Fortunately, most cases eventually clear on their own and do not involve associated morbidity.
ANSWER
The item that does not belong is tinea corporis (ringworm; choice “c”). There are several reasons this presumed, “obvious” diagnosis does not belong: First, there was no known source (human or animal) from which the patient could have contracted such an infection. Second, what should have been adequate treatment for a fungal infection had no effect. And finally, cutaneous fungal infections almost always disrupt the outer layer of skin; the relevant signs (eg, scaling, vesiculation, follicular granulomas) were absent in this case.
The correct diagnosis is granuloma annulare (GA; choice “a”), an extremely common, benign condition that is often misdiagnosed and treated as fungal infection. Histologically, GA is characterized by palisading (row-like) collections of cells that group together to form granulomas.
Similar patterns can be seen with sarcoidosis (choice “b”) and cutaneous mycobacterial infection (choice “d”), but additional distinguishing histologic features must be sought to confirm those diagnoses.
DISCUSSION
Virtually every medical provider has fallen for this clinical canard, referring an alleged “fungal infection” to dermatology when it fails to respond to treatment. This case was archetypical of GA, a condition most commonly found on the feet of young women.
It manifests on the extensor surfaces of the extremities as brownish red, round-to-oval, intradermal plaques devoid of surface disruption. The borders of the lesions are often raised enough to produce an apparent valley (delling) in the center.
There is a rather wide spectrum of GA variants (eg, generalized, su
Many treatments have been used (including topical or intralesional steroids and liquid nitrogen), but none are particularly effective. Fortunately, most cases eventually clear on their own and do not involve associated morbidity.
ANSWER
The item that does not belong is tinea corporis (ringworm; choice “c”). There are several reasons this presumed, “obvious” diagnosis does not belong: First, there was no known source (human or animal) from which the patient could have contracted such an infection. Second, what should have been adequate treatment for a fungal infection had no effect. And finally, cutaneous fungal infections almost always disrupt the outer layer of skin; the relevant signs (eg, scaling, vesiculation, follicular granulomas) were absent in this case.
The correct diagnosis is granuloma annulare (GA; choice “a”), an extremely common, benign condition that is often misdiagnosed and treated as fungal infection. Histologically, GA is characterized by palisading (row-like) collections of cells that group together to form granulomas.
Similar patterns can be seen with sarcoidosis (choice “b”) and cutaneous mycobacterial infection (choice “d”), but additional distinguishing histologic features must be sought to confirm those diagnoses.
DISCUSSION
Virtually every medical provider has fallen for this clinical canard, referring an alleged “fungal infection” to dermatology when it fails to respond to treatment. This case was archetypical of GA, a condition most commonly found on the feet of young women.
It manifests on the extensor surfaces of the extremities as brownish red, round-to-oval, intradermal plaques devoid of surface disruption. The borders of the lesions are often raised enough to produce an apparent valley (delling) in the center.
There is a rather wide spectrum of GA variants (eg, generalized, su
Many treatments have been used (including topical or intralesional steroids and liquid nitrogen), but none are particularly effective. Fortunately, most cases eventually clear on their own and do not involve associated morbidity.
Two years ago, asymptomatic lesions appeared on this 17-year-old girl’s left foot. Diagnosed as “ringworm” by primary care, the spots have not responded to topical econazole or oral terbinafine and have instead grown and darkened.
Five intradermal plaques are found on the dorsal aspect of the patient’s left foot. Round and reddish brown, they measure 3 to 4 cm each. There is modest induration on palpation, but no increased warmth or tenderness. None of the lesions have an epidermal component (ie, scaling, vesiculation); in short, there is nothing to scrape for KOH examination.
The patient has no lesions elsewhere and denies any other health problems. Her mother, who is present, is certain that no one else in the family has had similar lesions. There are no pets in the house.
Even Grandma Can’t Cure This
ANSWER
The correct answer is nummular eczema (NE; choice “c”).
Although fairly common, NE is not a well-known diagnostic entity. Its round shape and scaly surface are often misdiagnosed as fungal infection (choice “a”). But such an infection would have responded to the prescribed medication. In addition, there was no likely source (a new cat, dog, or ferret; participation in a contact sport, such as wrestling), making this diagnosis unlikely.
The scale of psoriasis (choice “b”) is typically white, tenacious, and much thicker than that seen in this case. Other signs would have been visible on the knees, elbows, scalp, or nails.
Impetigo (choice “d”), a superficial skin infection caused by staph and/or strep, first requires a break in the skin to gain entry (eg, picked-over acne, scratches). It manifests with a honey-colored crust on a red base, which were missing in this case.
DISCUSSION
NE is fairly common (seen in every 1 per 1,000 dermatology visits) and can be found on the arms as well as the legs. Predisposing factors include atopy and dry skin—but truth be told, there are many aspects of this condition that remain unexplained. While histopathologic studies can confirm the diagnosis, they offer little explanation of its origin.
What we do know: NE usually begins with a tiny papule, then a surrounding scaly rash develops as the papule disappears. The lesions, which can appear in multiples, are benign and will eventually clear on their own. This is fortunate, because NE can be very difficult to treat.
In this case, the standard regimen was prescribed: a class I topical steroid (clobetasol) to be used under occlusion. For prevention, patients should avoid scented, colored products; long, hot showers (or hot tubs); and heavy moisturizers.
But the bigger take-home message is that not all round, scaly lesions are of fungal origin. The differential includes several items—NE among them.
ANSWER
The correct answer is nummular eczema (NE; choice “c”).
Although fairly common, NE is not a well-known diagnostic entity. Its round shape and scaly surface are often misdiagnosed as fungal infection (choice “a”). But such an infection would have responded to the prescribed medication. In addition, there was no likely source (a new cat, dog, or ferret; participation in a contact sport, such as wrestling), making this diagnosis unlikely.
The scale of psoriasis (choice “b”) is typically white, tenacious, and much thicker than that seen in this case. Other signs would have been visible on the knees, elbows, scalp, or nails.
Impetigo (choice “d”), a superficial skin infection caused by staph and/or strep, first requires a break in the skin to gain entry (eg, picked-over acne, scratches). It manifests with a honey-colored crust on a red base, which were missing in this case.
DISCUSSION
NE is fairly common (seen in every 1 per 1,000 dermatology visits) and can be found on the arms as well as the legs. Predisposing factors include atopy and dry skin—but truth be told, there are many aspects of this condition that remain unexplained. While histopathologic studies can confirm the diagnosis, they offer little explanation of its origin.
What we do know: NE usually begins with a tiny papule, then a surrounding scaly rash develops as the papule disappears. The lesions, which can appear in multiples, are benign and will eventually clear on their own. This is fortunate, because NE can be very difficult to treat.
In this case, the standard regimen was prescribed: a class I topical steroid (clobetasol) to be used under occlusion. For prevention, patients should avoid scented, colored products; long, hot showers (or hot tubs); and heavy moisturizers.
But the bigger take-home message is that not all round, scaly lesions are of fungal origin. The differential includes several items—NE among them.
ANSWER
The correct answer is nummular eczema (NE; choice “c”).
Although fairly common, NE is not a well-known diagnostic entity. Its round shape and scaly surface are often misdiagnosed as fungal infection (choice “a”). But such an infection would have responded to the prescribed medication. In addition, there was no likely source (a new cat, dog, or ferret; participation in a contact sport, such as wrestling), making this diagnosis unlikely.
The scale of psoriasis (choice “b”) is typically white, tenacious, and much thicker than that seen in this case. Other signs would have been visible on the knees, elbows, scalp, or nails.
Impetigo (choice “d”), a superficial skin infection caused by staph and/or strep, first requires a break in the skin to gain entry (eg, picked-over acne, scratches). It manifests with a honey-colored crust on a red base, which were missing in this case.
DISCUSSION
NE is fairly common (seen in every 1 per 1,000 dermatology visits) and can be found on the arms as well as the legs. Predisposing factors include atopy and dry skin—but truth be told, there are many aspects of this condition that remain unexplained. While histopathologic studies can confirm the diagnosis, they offer little explanation of its origin.
What we do know: NE usually begins with a tiny papule, then a surrounding scaly rash develops as the papule disappears. The lesions, which can appear in multiples, are benign and will eventually clear on their own. This is fortunate, because NE can be very difficult to treat.
In this case, the standard regimen was prescribed: a class I topical steroid (clobetasol) to be used under occlusion. For prevention, patients should avoid scented, colored products; long, hot showers (or hot tubs); and heavy moisturizers.
But the bigger take-home message is that not all round, scaly lesions are of fungal origin. The differential includes several items—NE among them.
For several weeks, a 16-year-old girl has had an itchy rash on her calf. Her primary care provider, believing it to be fungal, prescribed nystatin cream and oral terbinafine (250 mg/d for a month). This treatment regimen had no effect.
In desperation, her grandmother mixed together a “family recipe” of peroxide, manteca (lard), and alcohol. This concoction was applied to the rash for several days—but alas, even this secret formula failed to bring improvement.
The patient has an extensive history of atopy, including eczema and seasonal allergies. The family has one small dog that stays indoors; there are no new pets in the household.
On the patient’s left medial calf is a round, well-defined, 4-cm patch of scaly skin. The lesion is brownish pink, consistent with her type IV skin. Closer inspection suggests the surface was initially covered with tiny blisters (vesicles); additional questioning confirms this.
Elsewhere, her skin is quite dry. No changes are seen on her knees, elbows, or scalp.
Scratching the Surface of the Problem
ANSWER
The least likely diagnosis is staph infection (choice “b”). By their very nature, staph infections are suppurative, often involving redness, swelling, pain, and purulent drainage. They can be chronic (eg, MRSA) but are more typically of acute onset. And they usually resolve on their own or with treatment; recall that this patient was treated for staph infection many times without any change.
She was also treated repeatedly for scabies (choice “a”), a condition that could certainly last 15 years. However, the lack of improvement with treatment, combined with the absence of suggestive signs, make this diagnosis improbable.
Mycosis fungoides (MF; choice “c”) is a type of T-cell lymphoma that often develops with itching and plaque formation over the course of years. It was ultimately ruled out by the biopsy results (as were scabies and staph infection).
What the biopsy did show was epidermal thickening—a characteristic sign of prurigo nodularis (choice “d”).
DISCUSSION
Prurigo nodularis is a localized form of neurodermatitis caused by picking and scratching. As with the classic form, the more the patient scratches, the more the lesions itch and multiply. In this case, biopsy of the larger plaque showed hypertrophic scarring.
The patient’s skin-picking habit likely developed during (and perhaps because of) her methamphetamine use. Long-term exposure to the itch-scratch-itch cycle can make treatment problematic. In this case, a class 4 topical steroid cream was prescribed, along with injection of several larger lesions with 10 mg/mL triamcinolone suspension.
It’s worth mentioning that for patients with this type of history, general lab testing (ie, complete blood count and complete metabolic panel) should be performed to rule out organic disease and other serious conditions (eg, renal or hepatic failure, leukemia). Fortunately, this patient’s results were reassuring on that front.
ANSWER
The least likely diagnosis is staph infection (choice “b”). By their very nature, staph infections are suppurative, often involving redness, swelling, pain, and purulent drainage. They can be chronic (eg, MRSA) but are more typically of acute onset. And they usually resolve on their own or with treatment; recall that this patient was treated for staph infection many times without any change.
She was also treated repeatedly for scabies (choice “a”), a condition that could certainly last 15 years. However, the lack of improvement with treatment, combined with the absence of suggestive signs, make this diagnosis improbable.
Mycosis fungoides (MF; choice “c”) is a type of T-cell lymphoma that often develops with itching and plaque formation over the course of years. It was ultimately ruled out by the biopsy results (as were scabies and staph infection).
What the biopsy did show was epidermal thickening—a characteristic sign of prurigo nodularis (choice “d”).
DISCUSSION
Prurigo nodularis is a localized form of neurodermatitis caused by picking and scratching. As with the classic form, the more the patient scratches, the more the lesions itch and multiply. In this case, biopsy of the larger plaque showed hypertrophic scarring.
The patient’s skin-picking habit likely developed during (and perhaps because of) her methamphetamine use. Long-term exposure to the itch-scratch-itch cycle can make treatment problematic. In this case, a class 4 topical steroid cream was prescribed, along with injection of several larger lesions with 10 mg/mL triamcinolone suspension.
It’s worth mentioning that for patients with this type of history, general lab testing (ie, complete blood count and complete metabolic panel) should be performed to rule out organic disease and other serious conditions (eg, renal or hepatic failure, leukemia). Fortunately, this patient’s results were reassuring on that front.
ANSWER
The least likely diagnosis is staph infection (choice “b”). By their very nature, staph infections are suppurative, often involving redness, swelling, pain, and purulent drainage. They can be chronic (eg, MRSA) but are more typically of acute onset. And they usually resolve on their own or with treatment; recall that this patient was treated for staph infection many times without any change.
She was also treated repeatedly for scabies (choice “a”), a condition that could certainly last 15 years. However, the lack of improvement with treatment, combined with the absence of suggestive signs, make this diagnosis improbable.
Mycosis fungoides (MF; choice “c”) is a type of T-cell lymphoma that often develops with itching and plaque formation over the course of years. It was ultimately ruled out by the biopsy results (as were scabies and staph infection).
What the biopsy did show was epidermal thickening—a characteristic sign of prurigo nodularis (choice “d”).
DISCUSSION
Prurigo nodularis is a localized form of neurodermatitis caused by picking and scratching. As with the classic form, the more the patient scratches, the more the lesions itch and multiply. In this case, biopsy of the larger plaque showed hypertrophic scarring.
The patient’s skin-picking habit likely developed during (and perhaps because of) her methamphetamine use. Long-term exposure to the itch-scratch-itch cycle can make treatment problematic. In this case, a class 4 topical steroid cream was prescribed, along with injection of several larger lesions with 10 mg/mL triamcinolone suspension.
It’s worth mentioning that for patients with this type of history, general lab testing (ie, complete blood count and complete metabolic panel) should be performed to rule out organic disease and other serious conditions (eg, renal or hepatic failure, leukemia). Fortunately, this patient’s results were reassuring on that front.
For at least 15 years, this 61-year-old African-American woman has had itchy lesions within arm’s reach. The patient says the problem manifested during a period in her life when she was addicted to several drugs, including methamphetamine. She complains bitterly about the itching and says it is difficult for her to leave the lesions alone.
No one else in her household is similarly affected. The patient has consulted a variety of health care providers, from primary care to dermatology and other specialties. She has received diagnoses of everything from scabies (for which she was treated, unsuccessfully) to pyoderma, bedbugs, and various forms of staph infection.
Examination reveals more than 100 lesions, mostly confined to her abdomen and lower chest, ranging from pinpoint to more than 3 cm. Many are excoriated, but most are purplish brown, oval plaques that somewhat match her type IV skin.
Her back, arms, and hands are spared. No lesions are seen between her fingers or on her volar wrists.
A biopsy is performed on two of the lesions—one small, the other larger.
Can’t Quite Put My Finger On It …
ANSWER
The correct answer is perform a shave biopsy (choice “c”). It is a bedrock principle in dermatology that there is no substitute for a correct diagnosis, because correct diagnosis dictates proper treatment. When practical, biopsy is an excellent way to establish the true nature of a lesion and rule out other possibilities; it cuts through all conjecture.
DISCUSSION
The report showed intraepidermal squamous cell carcinoma, also known as Bowen disease. In this case, overexposure to the sun was the probable cause; however, Bowen disease can also develop from non–UV-related triggers, including human papillomavirus, arsenic (usually in contaminated ground water), and radiation treatment.
The differential includes psoriasis (which waxes and wanes), fungal infection (unlikely to last 10 years with so little growth), and superficial basal cell carcinoma.
Treatment success can be achieved by electrodessication and curettage or by the application of 5-fluorouracil or imiquimod cream for a month or two. Rarely, Bowen lesions can become invasive and metastasize if left untreated.
This patient’s prognosis, however, is excellent—at least, as far as this lesion is concerned. His history of sun exposure and numerous skin cancers
ANSWER
The correct answer is perform a shave biopsy (choice “c”). It is a bedrock principle in dermatology that there is no substitute for a correct diagnosis, because correct diagnosis dictates proper treatment. When practical, biopsy is an excellent way to establish the true nature of a lesion and rule out other possibilities; it cuts through all conjecture.
DISCUSSION
The report showed intraepidermal squamous cell carcinoma, also known as Bowen disease. In this case, overexposure to the sun was the probable cause; however, Bowen disease can also develop from non–UV-related triggers, including human papillomavirus, arsenic (usually in contaminated ground water), and radiation treatment.
The differential includes psoriasis (which waxes and wanes), fungal infection (unlikely to last 10 years with so little growth), and superficial basal cell carcinoma.
Treatment success can be achieved by electrodessication and curettage or by the application of 5-fluorouracil or imiquimod cream for a month or two. Rarely, Bowen lesions can become invasive and metastasize if left untreated.
This patient’s prognosis, however, is excellent—at least, as far as this lesion is concerned. His history of sun exposure and numerous skin cancers
ANSWER
The correct answer is perform a shave biopsy (choice “c”). It is a bedrock principle in dermatology that there is no substitute for a correct diagnosis, because correct diagnosis dictates proper treatment. When practical, biopsy is an excellent way to establish the true nature of a lesion and rule out other possibilities; it cuts through all conjecture.
DISCUSSION
The report showed intraepidermal squamous cell carcinoma, also known as Bowen disease. In this case, overexposure to the sun was the probable cause; however, Bowen disease can also develop from non–UV-related triggers, including human papillomavirus, arsenic (usually in contaminated ground water), and radiation treatment.
The differential includes psoriasis (which waxes and wanes), fungal infection (unlikely to last 10 years with so little growth), and superficial basal cell carcinoma.
Treatment success can be achieved by electrodessication and curettage or by the application of 5-fluorouracil or imiquimod cream for a month or two. Rarely, Bowen lesions can become invasive and metastasize if left untreated.
This patient’s prognosis, however, is excellent—at least, as far as this lesion is concerned. His history of sun exposure and numerous skin cancers
For at least 10 years, a now 70-year-old man has had a lesion on his left third finger. It is asymptomatic but gradually growing larger. Various primary care providers have offered diagnoses, the most recent being “fungal infection,” but treatments including nystatin cream have had no good effect.
The oval, pink, scaly lesion is located on the medial aspect of the proximal phalanx of the patient’s left hand; it measures 2.3 cm with well-defined borders. It is barely palpable and is not at all tender. No nodes can be felt in the arm or axilla.
The patient is otherwise healthy and is not immunosuppressed. His skin elsewhere shows evidence of sun damage—including actinic keratosis, solar lentigines, and telangiectasias—and removal of several basal cell carcinomas from his face and arms. His elbows, knees, scalp, and nails are free of any notable skin changes.
