Quiz

ANSWER
The correct answer is to obtain a biopsy (choice “d”), the results of which would likely dictate rational and effective treatment. The other choices are largely empirical and not based on available evidence.

DISCUSSION
In this case, the biopsy (with samples from the arm rash as well as from the ears) showed unequivocal evidence of connective tissue disease—almost certainly lupus.

Systemic lupus erythematosus (SLE) has protean manifestations because it can affect so many different organs in so many different ways. Reduced to its simplest elements, lupus is an autoimmune process that results in a form of vasculitis that can affect any perfused tissue.

In terms of the skin, the visible manifestations of lupus are numerous and not always obvious. Sun is a known exacerbating factor, as this case demonstrated quite well: The patient’s rash was pronounced on sun-exposed skin but spared covered skin. When this was brought to her attention, the patient recalled a baby-sitting job earlier in the year (summer) that had required her to spend time outdoors. She also acknowledged that her smoking habit often took her into the backyard, where she would stand in the sun.

That being said, neither the arm rash nor the ear changes are “typical” of lupus (although the latter did include patulous follicular orifices, enlarged pores often seen focally with lupus). The effect is simply the result of the patient’s normal dark skin color; on a white person, the discoloration would have been pink or red.

Although these changes were suspicious for lupus, it was necessary to establish the diagnosis by biopsy—especially since the patient was already being treated for the disease. With that accomplished, the patient was sent back to her rheumatologist, who indicated he would probably treat her with a biologic, plus or minus methotrexate.

ANSWER
The correct answer is to obtain a biopsy (choice “d”), the results of which would likely dictate rational and effective treatment. The other choices are largely empirical and not based on available evidence.

DISCUSSION
In this case, the biopsy (with samples from the arm rash as well as from the ears) showed unequivocal evidence of connective tissue disease—almost certainly lupus.

Systemic lupus erythematosus (SLE) has protean manifestations because it can affect so many different organs in so many different ways. Reduced to its simplest elements, lupus is an autoimmune process that results in a form of vasculitis that can affect any perfused tissue.

In terms of the skin, the visible manifestations of lupus are numerous and not always obvious. Sun is a known exacerbating factor, as this case demonstrated quite well: The patient’s rash was pronounced on sun-exposed skin but spared covered skin. When this was brought to her attention, the patient recalled a baby-sitting job earlier in the year (summer) that had required her to spend time outdoors. She also acknowledged that her smoking habit often took her into the backyard, where she would stand in the sun.

That being said, neither the arm rash nor the ear changes are “typical” of lupus (although the latter did include patulous follicular orifices, enlarged pores often seen focally with lupus). The effect is simply the result of the patient’s normal dark skin color; on a white person, the discoloration would have been pink or red.

Although these changes were suspicious for lupus, it was necessary to establish the diagnosis by biopsy—especially since the patient was already being treated for the disease. With that accomplished, the patient was sent back to her rheumatologist, who indicated he would probably treat her with a biologic, plus or minus methotrexate.

ANSWER
The correct answer is to obtain a biopsy (choice “d”), the results of which would likely dictate rational and effective treatment. The other choices are largely empirical and not based on available evidence.

DISCUSSION
In this case, the biopsy (with samples from the arm rash as well as from the ears) showed unequivocal evidence of connective tissue disease—almost certainly lupus.

Systemic lupus erythematosus (SLE) has protean manifestations because it can affect so many different organs in so many different ways. Reduced to its simplest elements, lupus is an autoimmune process that results in a form of vasculitis that can affect any perfused tissue.

In terms of the skin, the visible manifestations of lupus are numerous and not always obvious. Sun is a known exacerbating factor, as this case demonstrated quite well: The patient’s rash was pronounced on sun-exposed skin but spared covered skin. When this was brought to her attention, the patient recalled a baby-sitting job earlier in the year (summer) that had required her to spend time outdoors. She also acknowledged that her smoking habit often took her into the backyard, where she would stand in the sun.

That being said, neither the arm rash nor the ear changes are “typical” of lupus (although the latter did include patulous follicular orifices, enlarged pores often seen focally with lupus). The effect is simply the result of the patient’s normal dark skin color; on a white person, the discoloration would have been pink or red.

Although these changes were suspicious for lupus, it was necessary to establish the diagnosis by biopsy—especially since the patient was already being treated for the disease. With that accomplished, the patient was sent back to her rheumatologist, who indicated he would probably treat her with a biologic, plus or minus methotrexate.

The Diagnosis: Hyperkeratosis Lenticularis Perstans

A shave biopsy of a lesion on the right leg was performed. Histopathology revealed a discrete papule with overlying compact hyperkeratosis. There was parakeratosis with an absent granular layer and a lichenoid lymphocytic infiltrate within the papillary dermis (Figure). Given the clinical context, these changes were consistent with a diagnosis of hyperkeratosis lenticularis perstans (HLP), also known as Flegel disease.

The patient was started on tretinoin cream 0.1% nightly for 3 months and triamcinolone ointment 0.1% as needed for pruritus but showed no clinical response. Given the benign nature of the condition and because the lesions were asymptomatic, additional treatment options were not pursued.

Originally described by Flegel¹ in 1958, HLP is a rare skin disorder commonly seen in white individuals with onset in the fourth or fifth decades of life.^1,2 While most cases are sporadic,^3-6 HLP also has been associated with autosomal dominant inheritance.^7-10

Patients with HLP typically present with multiple 1- to 5-mm reddish-brown, hyperkeratotic, scaly papules that reveal a moist, erythematous base with pinpoint bleeding upon removal of the scale. Lesions usually are distributed symmetrically and most commonly present on the extensor surfaces of the lower legs and dorsal feet.^1,2,7 Lesions also may appear on the extensor surfaces of the arms, pinna, periocular region, antecubital and popliteal fossae, and oral mucosa and also may present as pits on the palms and soles.^2,4,7,8 Furthermore, unilateral and localized variants of HLP have been described.^11,12 Hyperkeratosis lenticularis perstans usually is asymptomatic but can present with mild pruritus or burning.^3,5,13

The etiology and pathogenesis of HLP are unknown. Exposure to UV light has been implicated as an inciting factor¹⁴; however, reports of spontaneous resolution in the summer¹³ and upon treatment with psoralen plus UVA therapy¹⁵ make the role of UV light unclear. Furthermore, investigators disagree as to whether the primary pathogenic event in HLP is an inflammatory process or one of abnormal keratinization.^1,3,7,10 Fernandez-Flores and Manjon¹⁶ suggested HLP is an inflammatory process with periods of exacerbations and remissions after finding mounds of parakeratosis with neutrophils arranged in different strata in the stratum corneum.

Histologically, compact hyperkeratosis usually is noted, often with associated parakeratosis, epidermal atrophy with thinning or absence of the granular layer, and a bandlike lymphohistiocytic infiltrate in the papillary dermis.^1-3 Histopathologic differences between recent-onset versus longstanding lesions have been found, with old lesions lacking an inflammatory infiltrate.³ Furthermore, new lesions often show abnormalities in quantity and/or morphology of membrane-coating granules, also known as Odland bodies, in keratinocytes on electron microscopy,^3,10,17 while old lesions do not.³ Odland bodies are involved in normal desquamation, leading some to speculate on their role in HLP.¹⁰ Currently, it is unclear whether abnormalities in these organelles cause the retention hyperkeratosis seen in HLP or if such abnormalities are a secondary phenomenon.^3,17

There are questionable associations between HLP and diabetes mellitus type 2, hyperthyroidism, basal and squamous cell carcinomas of the skin, and gastrointestinal malignancy.^4,9,18 Our patient had a history of basal cell carcinoma on the face, diet-controlled diabetes mellitus, and hypothyroidism. Given the high prevalence of these diseases in the general population, however, it is difficult to ascertain whether a true association with HLP exists.

While HLP can slowly progress to involve additional body sites, it is overall a benign condition that does not require treatment. Therapeutic options are based on case reports, with no single treatment showing a consistent response. From review of the literature, therapies that have been most effective include dermabrasion, excision,¹⁹ topical 5-fluorouracil,^2,17,20 and oral retinoids.⁸ Hyperkeratosis lenticularis perstans generally is resistant to topical steroids, retinoids, and vitamin D₃ analogs, although success with betamethasone dipropionate,⁵ isotretinoin  
gel 0.05%,¹¹ and calcipotriol have been reported.⁶ A case of HLP with clinical response to psoralen plus UVA therapy also has been described.¹⁵

The Diagnosis: Hyperkeratosis Lenticularis Perstans

A shave biopsy of a lesion on the right leg was performed. Histopathology revealed a discrete papule with overlying compact hyperkeratosis. There was parakeratosis with an absent granular layer and a lichenoid lymphocytic infiltrate within the papillary dermis (Figure). Given the clinical context, these changes were consistent with a diagnosis of hyperkeratosis lenticularis perstans (HLP), also known as Flegel disease.

The patient was started on tretinoin cream 0.1% nightly for 3 months and triamcinolone ointment 0.1% as needed for pruritus but showed no clinical response. Given the benign nature of the condition and because the lesions were asymptomatic, additional treatment options were not pursued.

Originally described by Flegel¹ in 1958, HLP is a rare skin disorder commonly seen in white individuals with onset in the fourth or fifth decades of life.^1,2 While most cases are sporadic,^3-6 HLP also has been associated with autosomal dominant inheritance.^7-10

Patients with HLP typically present with multiple 1- to 5-mm reddish-brown, hyperkeratotic, scaly papules that reveal a moist, erythematous base with pinpoint bleeding upon removal of the scale. Lesions usually are distributed symmetrically and most commonly present on the extensor surfaces of the lower legs and dorsal feet.^1,2,7 Lesions also may appear on the extensor surfaces of the arms, pinna, periocular region, antecubital and popliteal fossae, and oral mucosa and also may present as pits on the palms and soles.^2,4,7,8 Furthermore, unilateral and localized variants of HLP have been described.^11,12 Hyperkeratosis lenticularis perstans usually is asymptomatic but can present with mild pruritus or burning.^3,5,13

The etiology and pathogenesis of HLP are unknown. Exposure to UV light has been implicated as an inciting factor¹⁴; however, reports of spontaneous resolution in the summer¹³ and upon treatment with psoralen plus UVA therapy¹⁵ make the role of UV light unclear. Furthermore, investigators disagree as to whether the primary pathogenic event in HLP is an inflammatory process or one of abnormal keratinization.^1,3,7,10 Fernandez-Flores and Manjon¹⁶ suggested HLP is an inflammatory process with periods of exacerbations and remissions after finding mounds of parakeratosis with neutrophils arranged in different strata in the stratum corneum.

Histologically, compact hyperkeratosis usually is noted, often with associated parakeratosis, epidermal atrophy with thinning or absence of the granular layer, and a bandlike lymphohistiocytic infiltrate in the papillary dermis.^1-3 Histopathologic differences between recent-onset versus longstanding lesions have been found, with old lesions lacking an inflammatory infiltrate.³ Furthermore, new lesions often show abnormalities in quantity and/or morphology of membrane-coating granules, also known as Odland bodies, in keratinocytes on electron microscopy,^3,10,17 while old lesions do not.³ Odland bodies are involved in normal desquamation, leading some to speculate on their role in HLP.¹⁰ Currently, it is unclear whether abnormalities in these organelles cause the retention hyperkeratosis seen in HLP or if such abnormalities are a secondary phenomenon.^3,17

There are questionable associations between HLP and diabetes mellitus type 2, hyperthyroidism, basal and squamous cell carcinomas of the skin, and gastrointestinal malignancy.^4,9,18 Our patient had a history of basal cell carcinoma on the face, diet-controlled diabetes mellitus, and hypothyroidism. Given the high prevalence of these diseases in the general population, however, it is difficult to ascertain whether a true association with HLP exists.

While HLP can slowly progress to involve additional body sites, it is overall a benign condition that does not require treatment. Therapeutic options are based on case reports, with no single treatment showing a consistent response. From review of the literature, therapies that have been most effective include dermabrasion, excision,¹⁹ topical 5-fluorouracil,^2,17,20 and oral retinoids.⁸ Hyperkeratosis lenticularis perstans generally is resistant to topical steroids, retinoids, and vitamin D₃ analogs, although success with betamethasone dipropionate,⁵ isotretinoin  
gel 0.05%,¹¹ and calcipotriol have been reported.⁶ A case of HLP with clinical response to psoralen plus UVA therapy also has been described.¹⁵

The Diagnosis: Hyperkeratosis Lenticularis Perstans

A shave biopsy of a lesion on the right leg was performed. Histopathology revealed a discrete papule with overlying compact hyperkeratosis. There was parakeratosis with an absent granular layer and a lichenoid lymphocytic infiltrate within the papillary dermis (Figure). Given the clinical context, these changes were consistent with a diagnosis of hyperkeratosis lenticularis perstans (HLP), also known as Flegel disease.

The patient was started on tretinoin cream 0.1% nightly for 3 months and triamcinolone ointment 0.1% as needed for pruritus but showed no clinical response. Given the benign nature of the condition and because the lesions were asymptomatic, additional treatment options were not pursued.

Originally described by Flegel¹ in 1958, HLP is a rare skin disorder commonly seen in white individuals with onset in the fourth or fifth decades of life.^1,2 While most cases are sporadic,^3-6 HLP also has been associated with autosomal dominant inheritance.^7-10

Patients with HLP typically present with multiple 1- to 5-mm reddish-brown, hyperkeratotic, scaly papules that reveal a moist, erythematous base with pinpoint bleeding upon removal of the scale. Lesions usually are distributed symmetrically and most commonly present on the extensor surfaces of the lower legs and dorsal feet.^1,2,7 Lesions also may appear on the extensor surfaces of the arms, pinna, periocular region, antecubital and popliteal fossae, and oral mucosa and also may present as pits on the palms and soles.^2,4,7,8 Furthermore, unilateral and localized variants of HLP have been described.^11,12 Hyperkeratosis lenticularis perstans usually is asymptomatic but can present with mild pruritus or burning.^3,5,13

The etiology and pathogenesis of HLP are unknown. Exposure to UV light has been implicated as an inciting factor¹⁴; however, reports of spontaneous resolution in the summer¹³ and upon treatment with psoralen plus UVA therapy¹⁵ make the role of UV light unclear. Furthermore, investigators disagree as to whether the primary pathogenic event in HLP is an inflammatory process or one of abnormal keratinization.^1,3,7,10 Fernandez-Flores and Manjon¹⁶ suggested HLP is an inflammatory process with periods of exacerbations and remissions after finding mounds of parakeratosis with neutrophils arranged in different strata in the stratum corneum.

Histologically, compact hyperkeratosis usually is noted, often with associated parakeratosis, epidermal atrophy with thinning or absence of the granular layer, and a bandlike lymphohistiocytic infiltrate in the papillary dermis.^1-3 Histopathologic differences between recent-onset versus longstanding lesions have been found, with old lesions lacking an inflammatory infiltrate.³ Furthermore, new lesions often show abnormalities in quantity and/or morphology of membrane-coating granules, also known as Odland bodies, in keratinocytes on electron microscopy,^3,10,17 while old lesions do not.³ Odland bodies are involved in normal desquamation, leading some to speculate on their role in HLP.¹⁰ Currently, it is unclear whether abnormalities in these organelles cause the retention hyperkeratosis seen in HLP or if such abnormalities are a secondary phenomenon.^3,17

There are questionable associations between HLP and diabetes mellitus type 2, hyperthyroidism, basal and squamous cell carcinomas of the skin, and gastrointestinal malignancy.^4,9,18 Our patient had a history of basal cell carcinoma on the face, diet-controlled diabetes mellitus, and hypothyroidism. Given the high prevalence of these diseases in the general population, however, it is difficult to ascertain whether a true association with HLP exists.

While HLP can slowly progress to involve additional body sites, it is overall a benign condition that does not require treatment. Therapeutic options are based on case reports, with no single treatment showing a consistent response. From review of the literature, therapies that have been most effective include dermabrasion, excision,¹⁹ topical 5-fluorouracil,^2,17,20 and oral retinoids.⁸ Hyperkeratosis lenticularis perstans generally is resistant to topical steroids, retinoids, and vitamin D₃ analogs, although success with betamethasone dipropionate,⁵ isotretinoin  
gel 0.05%,¹¹ and calcipotriol have been reported.⁶ A case of HLP with clinical response to psoralen plus UVA therapy also has been described.¹⁵

ANSWER
This ECG is representative of marked sinus bradycardia with second-degree atrioventricular block (Mobitz I) with an occasional junctional escape, left-axis deviation, and poor R-wave progression in the precordial leads.

Marked sinus bradycardia is evidenced by P waves that are regular except where expected, prior to the third QRS complex on the rhythm strip (lead 1).

Second-­degree Mobitz I (Wenckebach) block is indicated by a gradual prolonging of the PR interval until there is loss of conduction from the atria to the ventricle (following the third P wave). Careful inspection of the third QRS complex shows a slight difference in the normally conducted sinus beat, indicative of a junctional escape beat. Left-axis deviation entails an R-wave axis of –78°.

Finally, there is poor R-wave progression in the precordial leads, including the lateral leads.

Although Mobitz I block is not an indication for pacemaker placement, symptomatic bradycardia is. The patient underwent implantation of a dual-chamber permanent pacemaker, with complete resolution of symptoms.

ANSWER
This ECG is representative of marked sinus bradycardia with second-degree atrioventricular block (Mobitz I) with an occasional junctional escape, left-axis deviation, and poor R-wave progression in the precordial leads.

Marked sinus bradycardia is evidenced by P waves that are regular except where expected, prior to the third QRS complex on the rhythm strip (lead 1).

Second-­degree Mobitz I (Wenckebach) block is indicated by a gradual prolonging of the PR interval until there is loss of conduction from the atria to the ventricle (following the third P wave). Careful inspection of the third QRS complex shows a slight difference in the normally conducted sinus beat, indicative of a junctional escape beat. Left-axis deviation entails an R-wave axis of –78°.

Finally, there is poor R-wave progression in the precordial leads, including the lateral leads.

Although Mobitz I block is not an indication for pacemaker placement, symptomatic bradycardia is. The patient underwent implantation of a dual-chamber permanent pacemaker, with complete resolution of symptoms.

ANSWER
This ECG is representative of marked sinus bradycardia with second-degree atrioventricular block (Mobitz I) with an occasional junctional escape, left-axis deviation, and poor R-wave progression in the precordial leads.

Marked sinus bradycardia is evidenced by P waves that are regular except where expected, prior to the third QRS complex on the rhythm strip (lead 1).

Second-­degree Mobitz I (Wenckebach) block is indicated by a gradual prolonging of the PR interval until there is loss of conduction from the atria to the ventricle (following the third P wave). Careful inspection of the third QRS complex shows a slight difference in the normally conducted sinus beat, indicative of a junctional escape beat. Left-axis deviation entails an R-wave axis of –78°.

Finally, there is poor R-wave progression in the precordial leads, including the lateral leads.

Although Mobitz I block is not an indication for pacemaker placement, symptomatic bradycardia is. The patient underwent implantation of a dual-chamber permanent pacemaker, with complete resolution of symptoms.

ANSWER
The correct interpretation is coarse atrial fibrillation with a rapid ventricular response and left-axis deviation.

Coarse atrial fibrillation is evidenced by the irregularly irregular rhythm with a normal QRS duration and flutter/fibrillation waves arising from the atria. Rapid ventricular response is defined as a ventricular response > 100 beats/min (seen in this case). Finally, an R-wave axis between –30° and –90° is indicative of left-axis deviation.

Correcting the patient’s hypokalemia and hypomagnesemia resulted in a return to normal sinus rhythm. At one-year follow-up, he had had no further episodes of atrial fibrillation.

ANSWER
The correct interpretation is coarse atrial fibrillation with a rapid ventricular response and left-axis deviation.

Coarse atrial fibrillation is evidenced by the irregularly irregular rhythm with a normal QRS duration and flutter/fibrillation waves arising from the atria. Rapid ventricular response is defined as a ventricular response > 100 beats/min (seen in this case). Finally, an R-wave axis between –30° and –90° is indicative of left-axis deviation.

Correcting the patient’s hypokalemia and hypomagnesemia resulted in a return to normal sinus rhythm. At one-year follow-up, he had had no further episodes of atrial fibrillation.

ANSWER
The correct interpretation is coarse atrial fibrillation with a rapid ventricular response and left-axis deviation.

Coarse atrial fibrillation is evidenced by the irregularly irregular rhythm with a normal QRS duration and flutter/fibrillation waves arising from the atria. Rapid ventricular response is defined as a ventricular response > 100 beats/min (seen in this case). Finally, an R-wave axis between –30° and –90° is indicative of left-axis deviation.

Correcting the patient’s hypokalemia and hypomagnesemia resulted in a return to normal sinus rhythm. At one-year follow-up, he had had no further episodes of atrial fibrillation.

ANSWER
The radiograph shows a slightly displaced fracture of the distal fourth metacarpal head. No other injuries are present.

The patient’s hand was left in the splint, and orthopedic evaluation was obtained. 

ANSWER
The radiograph shows a slightly displaced fracture of the distal fourth metacarpal head. No other injuries are present.

The patient’s hand was left in the splint, and orthopedic evaluation was obtained. 

ANSWER
The radiograph shows a slightly displaced fracture of the distal fourth metacarpal head. No other injuries are present.

The patient’s hand was left in the splint, and orthopedic evaluation was obtained. 

ANSWER
The correct answer is all of the above (choice “e”). This particular form of tinea capitis is called black dot tinea capitis (BDTC), a somewhat unusual dermatophytosis (superficial fungal infection) that mostly affects children. The causative organisms are anthropophilic—that is, acquired from human sources, such as other children, during activities that involve skin-to-skin contact (eg, sports).

The vast majority of these organisms are from the Trichophyton family, such as T tonsurans or T violaceum. They invade the hair shaft itself, leaving the hard covering (the cuticle) intact. The black dots represent the tips of broken-off hairs, themselves full of fungal elements, seen in the photomicrograph. The term endothrix is given to this kind of fungal infection, in which the organisms are contained within the hair shaft, which, as a result, becomes brittle and breaks off. This is a relatively common type of infection.

A more unusual form of tinea capitis is caused by zoophilic organisms, such as Microsporum canis (from dogs and cats), Microsporum gypseum (pigs or cows), or T equinum (horses). These infect the external surface of the hair shaft, breaking down the cuticle. This allows for identification of the infection by Wood’s lamp, which causes the affected area to turn a yellowish color. These infections also tend to provoke a more brisk inflammatory response in the victim and are more difficult to treat.

Diagnosis can be made from a combination of clinical findings, KOH prep (as in this patient), and/or fungal culture.

Treatment can entail griseofulvin or terbinafine; the case patient was treated with a two-month course of the latter (125 mg/d). Topical treatment is of limited usefulness.

ANSWER
The correct answer is all of the above (choice “e”). This particular form of tinea capitis is called black dot tinea capitis (BDTC), a somewhat unusual dermatophytosis (superficial fungal infection) that mostly affects children. The causative organisms are anthropophilic—that is, acquired from human sources, such as other children, during activities that involve skin-to-skin contact (eg, sports).

The vast majority of these organisms are from the Trichophyton family, such as T tonsurans or T violaceum. They invade the hair shaft itself, leaving the hard covering (the cuticle) intact. The black dots represent the tips of broken-off hairs, themselves full of fungal elements, seen in the photomicrograph. The term endothrix is given to this kind of fungal infection, in which the organisms are contained within the hair shaft, which, as a result, becomes brittle and breaks off. This is a relatively common type of infection.

A more unusual form of tinea capitis is caused by zoophilic organisms, such as Microsporum canis (from dogs and cats), Microsporum gypseum (pigs or cows), or T equinum (horses). These infect the external surface of the hair shaft, breaking down the cuticle. This allows for identification of the infection by Wood’s lamp, which causes the affected area to turn a yellowish color. These infections also tend to provoke a more brisk inflammatory response in the victim and are more difficult to treat.

Diagnosis can be made from a combination of clinical findings, KOH prep (as in this patient), and/or fungal culture.

Treatment can entail griseofulvin or terbinafine; the case patient was treated with a two-month course of the latter (125 mg/d). Topical treatment is of limited usefulness.

ANSWER
The correct answer is all of the above (choice “e”). This particular form of tinea capitis is called black dot tinea capitis (BDTC), a somewhat unusual dermatophytosis (superficial fungal infection) that mostly affects children. The causative organisms are anthropophilic—that is, acquired from human sources, such as other children, during activities that involve skin-to-skin contact (eg, sports).

The vast majority of these organisms are from the Trichophyton family, such as T tonsurans or T violaceum. They invade the hair shaft itself, leaving the hard covering (the cuticle) intact. The black dots represent the tips of broken-off hairs, themselves full of fungal elements, seen in the photomicrograph. The term endothrix is given to this kind of fungal infection, in which the organisms are contained within the hair shaft, which, as a result, becomes brittle and breaks off. This is a relatively common type of infection.

A more unusual form of tinea capitis is caused by zoophilic organisms, such as Microsporum canis (from dogs and cats), Microsporum gypseum (pigs or cows), or T equinum (horses). These infect the external surface of the hair shaft, breaking down the cuticle. This allows for identification of the infection by Wood’s lamp, which causes the affected area to turn a yellowish color. These infections also tend to provoke a more brisk inflammatory response in the victim and are more difficult to treat.

Diagnosis can be made from a combination of clinical findings, KOH prep (as in this patient), and/or fungal culture.

Treatment can entail griseofulvin or terbinafine; the case patient was treated with a two-month course of the latter (125 mg/d). Topical treatment is of limited usefulness.

ANSWER
The radiograph shows a fracture of both the distal radius and distal ulna. The patient was placed in a splint and referred to orthopedics for outpatient follow-up.

ANSWER
The radiograph shows a fracture of both the distal radius and distal ulna. The patient was placed in a splint and referred to orthopedics for outpatient follow-up.

ANSWER
The radiograph shows a fracture of both the distal radius and distal ulna. The patient was placed in a splint and referred to orthopedics for outpatient follow-up.

ANSWER
The correct interpretation includes atrial fibrillation with a rapid ventricular response and aberrantly conducted complexes, left axis deviation, and a left bundle branch block.

Atrial fibrillation is evidenced by the irregularly irregular heart rhythm without a measurable PR interval, and the rapid ventricular response is indicated by a ventricular rate > 100 beats/min.

Aberrant conduction, caused by conduction delay down the His-Purkinje system, is evidenced by the wide QRS complexes with a normally conducted beat (see first beat in leads V₁-V₃). Criteria for left axis deviation include an R axis between –30° and –90°, and left bundle branch block criteria include a QRS duration > 120 ms, a dominant S wave in V₁, and broad monophasic R waves in leads I, aVL, and V₅-V₆.

ANSWER
The correct interpretation includes atrial fibrillation with a rapid ventricular response and aberrantly conducted complexes, left axis deviation, and a left bundle branch block.

Atrial fibrillation is evidenced by the irregularly irregular heart rhythm without a measurable PR interval, and the rapid ventricular response is indicated by a ventricular rate > 100 beats/min.

Aberrant conduction, caused by conduction delay down the His-Purkinje system, is evidenced by the wide QRS complexes with a normally conducted beat (see first beat in leads V₁-V₃). Criteria for left axis deviation include an R axis between –30° and –90°, and left bundle branch block criteria include a QRS duration > 120 ms, a dominant S wave in V₁, and broad monophasic R waves in leads I, aVL, and V₅-V₆.

ANSWER
The correct interpretation includes atrial fibrillation with a rapid ventricular response and aberrantly conducted complexes, left axis deviation, and a left bundle branch block.

Atrial fibrillation is evidenced by the irregularly irregular heart rhythm without a measurable PR interval, and the rapid ventricular response is indicated by a ventricular rate > 100 beats/min.

Aberrant conduction, caused by conduction delay down the His-Purkinje system, is evidenced by the wide QRS complexes with a normally conducted beat (see first beat in leads V₁-V₃). Criteria for left axis deviation include an R axis between –30° and –90°, and left bundle branch block criteria include a QRS duration > 120 ms, a dominant S wave in V₁, and broad monophasic R waves in leads I, aVL, and V₅-V₆.

ANSWER
The correct answer is erythema nodosum (EN; choice “c”), a reactive form of septal panniculitis with many potential triggers.

Erythema induratum (choice “a”) is a manifestation of lobular panniculitis, which affects the fat lobules but not the septae. It too has numerous triggers, but it tends to manifest with more discrete nodules, which eventually open and drain. It is far less common than EN.

Urticaria (choice “b”), also known as hives, presents as itchy, stingy wheals that are typically evanescent (eg, they appear suddenly, within seconds, and disappear within hours). Despite the itching and stinging, urticaria rarely hurts when it presents on the skin.

Erysipelas (choice “d”) is a superficial form of skin infection. More superficial than cellulitis, it usually is caused by a member of the Streptococcus family. It has a bright red appearance and sharply demarcated margins, with a peau d’orange (dimpled, like an orange peel) effect on its surface. It is acute in origin and responds readily to most common anti­biotics.

DISCUSSION
Erythema nodosum, a reactive process involving fibrous septae that support and separate subcutaneous adipocytes, is notable for the complete lack of epidermal change (eg, scaling, broken skin, pointing, draining). The incidence is about 2 in 10,000 population, with women outnumbering men at a rate of 4:1 and the 18-to-34 age-group most affected. The anterior leg is involved in the vast majority of cases.

EN often starts with flulike symptoms, followed by the appearance of discrete, bright red nodules, measuring 2 to 4 cm, on the anterior legs; these darken and coalesce over a period of seven to 10 weeks. New lesions can continue to appear for up to six weeks. As they progress, the lesions often become ecchymotic. Idiopathic cases (at least 20%) can last months.

Notable triggers include Crohn disease flares and use of drugs such as sulfa, gold salts, and oral contraceptives. Several infections have been identified as triggers, including strep, mycoplasma, and campylobacter, as well as deep fungal infections (histoplasmosis, blastomycosis, coccidioidomycosis, and sporotrichosis). More unusual causes include pregnancy and diseases such as sarcoidosis, tuberculosis, Behçet disease, and leukemia/lymphoma.

The diagnostic workup for EN includes punch biopsy of deep adipose tissue and throat culture, and when indicated, ASO titer (if strep is suspected) and chest films (to rule out tuberculosis and sarcoid). In most cases, the diagnosis can be made on clinical grounds alone, although the triggering entity may be difficult to identify. The identification and elimination of the underlying trigger is nonetheless crucial for diagnosis and treatment.

That issue aside, most cases of EN resolve with minimal treatment; this can include the use of NSAIDs and elevation of the limbs when possible. In this particular case, the intense pain the patient was experiencing called for stronger therapy (ibuprofen 800 mg tid, plus a two-week taper of prednisone 40 mg). She responded quite well, and the problem was almost totally resolved at a follow-up visit several weeks later.

In the absence of findings to the contrary, it is likely that the trigger for this patient’s EN was strep, given the timing of its manifestation after a sore throat.

ANSWER
The correct answer is erythema nodosum (EN; choice “c”), a reactive form of septal panniculitis with many potential triggers.

Erythema induratum (choice “a”) is a manifestation of lobular panniculitis, which affects the fat lobules but not the septae. It too has numerous triggers, but it tends to manifest with more discrete nodules, which eventually open and drain. It is far less common than EN.

Urticaria (choice “b”), also known as hives, presents as itchy, stingy wheals that are typically evanescent (eg, they appear suddenly, within seconds, and disappear within hours). Despite the itching and stinging, urticaria rarely hurts when it presents on the skin.

Erysipelas (choice “d”) is a superficial form of skin infection. More superficial than cellulitis, it usually is caused by a member of the Streptococcus family. It has a bright red appearance and sharply demarcated margins, with a peau d’orange (dimpled, like an orange peel) effect on its surface. It is acute in origin and responds readily to most common anti­biotics.

DISCUSSION
Erythema nodosum, a reactive process involving fibrous septae that support and separate subcutaneous adipocytes, is notable for the complete lack of epidermal change (eg, scaling, broken skin, pointing, draining). The incidence is about 2 in 10,000 population, with women outnumbering men at a rate of 4:1 and the 18-to-34 age-group most affected. The anterior leg is involved in the vast majority of cases.

EN often starts with flulike symptoms, followed by the appearance of discrete, bright red nodules, measuring 2 to 4 cm, on the anterior legs; these darken and coalesce over a period of seven to 10 weeks. New lesions can continue to appear for up to six weeks. As they progress, the lesions often become ecchymotic. Idiopathic cases (at least 20%) can last months.

Notable triggers include Crohn disease flares and use of drugs such as sulfa, gold salts, and oral contraceptives. Several infections have been identified as triggers, including strep, mycoplasma, and campylobacter, as well as deep fungal infections (histoplasmosis, blastomycosis, coccidioidomycosis, and sporotrichosis). More unusual causes include pregnancy and diseases such as sarcoidosis, tuberculosis, Behçet disease, and leukemia/lymphoma.

The diagnostic workup for EN includes punch biopsy of deep adipose tissue and throat culture, and when indicated, ASO titer (if strep is suspected) and chest films (to rule out tuberculosis and sarcoid). In most cases, the diagnosis can be made on clinical grounds alone, although the triggering entity may be difficult to identify. The identification and elimination of the underlying trigger is nonetheless crucial for diagnosis and treatment.

That issue aside, most cases of EN resolve with minimal treatment; this can include the use of NSAIDs and elevation of the limbs when possible. In this particular case, the intense pain the patient was experiencing called for stronger therapy (ibuprofen 800 mg tid, plus a two-week taper of prednisone 40 mg). She responded quite well, and the problem was almost totally resolved at a follow-up visit several weeks later.

In the absence of findings to the contrary, it is likely that the trigger for this patient’s EN was strep, given the timing of its manifestation after a sore throat.

ANSWER
The correct answer is erythema nodosum (EN; choice “c”), a reactive form of septal panniculitis with many potential triggers.

Erythema induratum (choice “a”) is a manifestation of lobular panniculitis, which affects the fat lobules but not the septae. It too has numerous triggers, but it tends to manifest with more discrete nodules, which eventually open and drain. It is far less common than EN.

Urticaria (choice “b”), also known as hives, presents as itchy, stingy wheals that are typically evanescent (eg, they appear suddenly, within seconds, and disappear within hours). Despite the itching and stinging, urticaria rarely hurts when it presents on the skin.

Erysipelas (choice “d”) is a superficial form of skin infection. More superficial than cellulitis, it usually is caused by a member of the Streptococcus family. It has a bright red appearance and sharply demarcated margins, with a peau d’orange (dimpled, like an orange peel) effect on its surface. It is acute in origin and responds readily to most common anti­biotics.

DISCUSSION
Erythema nodosum, a reactive process involving fibrous septae that support and separate subcutaneous adipocytes, is notable for the complete lack of epidermal change (eg, scaling, broken skin, pointing, draining). The incidence is about 2 in 10,000 population, with women outnumbering men at a rate of 4:1 and the 18-to-34 age-group most affected. The anterior leg is involved in the vast majority of cases.

EN often starts with flulike symptoms, followed by the appearance of discrete, bright red nodules, measuring 2 to 4 cm, on the anterior legs; these darken and coalesce over a period of seven to 10 weeks. New lesions can continue to appear for up to six weeks. As they progress, the lesions often become ecchymotic. Idiopathic cases (at least 20%) can last months.

Notable triggers include Crohn disease flares and use of drugs such as sulfa, gold salts, and oral contraceptives. Several infections have been identified as triggers, including strep, mycoplasma, and campylobacter, as well as deep fungal infections (histoplasmosis, blastomycosis, coccidioidomycosis, and sporotrichosis). More unusual causes include pregnancy and diseases such as sarcoidosis, tuberculosis, Behçet disease, and leukemia/lymphoma.

The diagnostic workup for EN includes punch biopsy of deep adipose tissue and throat culture, and when indicated, ASO titer (if strep is suspected) and chest films (to rule out tuberculosis and sarcoid). In most cases, the diagnosis can be made on clinical grounds alone, although the triggering entity may be difficult to identify. The identification and elimination of the underlying trigger is nonetheless crucial for diagnosis and treatment.

That issue aside, most cases of EN resolve with minimal treatment; this can include the use of NSAIDs and elevation of the limbs when possible. In this particular case, the intense pain the patient was experiencing called for stronger therapy (ibuprofen 800 mg tid, plus a two-week taper of prednisone 40 mg). She responded quite well, and the problem was almost totally resolved at a follow-up visit several weeks later.

In the absence of findings to the contrary, it is likely that the trigger for this patient’s EN was strep, given the timing of its manifestation after a sore throat.

The Diagnosis: Porokeratosis of Mibelli

There are 5 variants of porokeratosis: disseminated superficial actinic porokeratosis (DSAP), linear porokeratosis, porokeratosis of Mibelli, porokeratosis palmaris et plantaris disseminata, and punctate porokeratosis. The most common type is DSAP,¹ which is characterized by multiple lesions on the body, particularly in sun-exposed areas. The distinguishing feature of porokeratosis is the cornoid lamella, which is made up of parakeratotic cells extending through the stratum corneum. There also is a thin or absent granular layer beneath it (Figure).²

Patients generally present in the third and fourth decades of life.¹ Risk factors for porokeratosis include sun exposure, immunosuppression, and genetics.^2-4 Overexpression of the protein p53 in porokeratosis lesions has been demonstrated in studies investigating the genetics of porokeratosis.^5,6 A study of Chinese families with DSAP identified 3 different loci associated with DSAP: DSAP1, DSAP2, and DSAP3.² The progression to cancer has been noted in all types of porokeratosis lesions. Malignancies include squamous cell carcinoma, Bowen disease, and basal cell carcinoma.^7,8

Many treatments have been tried for DSAP including cryotherapy, topical 5-fluorouracil, photodynamic therapy, and topical imiquimod with varying success.¹ Our patient was treated with 
cryotherapy but had side effects from treatment including cellulitis and local infections with ulceration before finally healing.

Interestingly, our patient had a single lesion with pathology findings most consistent with DSAP at a later age. Although the pathology suggested DSAP, the size and solitary lesion was more consistent with porokeratosis of Mibelli. Porokeratosis of Mibelli can occur concurrently with DSAP,⁹ but we have not seen other lesions in this patient. We have educated our patient to be aware of other lesions that may occur in the future. Due to risk for malignant conversion, it is generally viewed as beneficial to treat patients who present with porokeratosis lesions. Our patient’s lesion ultimately cleared and he has not developed new lesions at 1-year follow-up.

Although DSAP generally presents in the third and fourth decades of life and porokeratosis of Mibelli during childhood, it is important to educate both dermatologists and primary care physicians to be aware of the possibility of both diagnoses in the elderly population.

The Diagnosis: Porokeratosis of Mibelli

There are 5 variants of porokeratosis: disseminated superficial actinic porokeratosis (DSAP), linear porokeratosis, porokeratosis of Mibelli, porokeratosis palmaris et plantaris disseminata, and punctate porokeratosis. The most common type is DSAP,¹ which is characterized by multiple lesions on the body, particularly in sun-exposed areas. The distinguishing feature of porokeratosis is the cornoid lamella, which is made up of parakeratotic cells extending through the stratum corneum. There also is a thin or absent granular layer beneath it (Figure).²

Patients generally present in the third and fourth decades of life.¹ Risk factors for porokeratosis include sun exposure, immunosuppression, and genetics.^2-4 Overexpression of the protein p53 in porokeratosis lesions has been demonstrated in studies investigating the genetics of porokeratosis.^5,6 A study of Chinese families with DSAP identified 3 different loci associated with DSAP: DSAP1, DSAP2, and DSAP3.² The progression to cancer has been noted in all types of porokeratosis lesions. Malignancies include squamous cell carcinoma, Bowen disease, and basal cell carcinoma.^7,8

Many treatments have been tried for DSAP including cryotherapy, topical 5-fluorouracil, photodynamic therapy, and topical imiquimod with varying success.¹ Our patient was treated with 
cryotherapy but had side effects from treatment including cellulitis and local infections with ulceration before finally healing.

Interestingly, our patient had a single lesion with pathology findings most consistent with DSAP at a later age. Although the pathology suggested DSAP, the size and solitary lesion was more consistent with porokeratosis of Mibelli. Porokeratosis of Mibelli can occur concurrently with DSAP,⁹ but we have not seen other lesions in this patient. We have educated our patient to be aware of other lesions that may occur in the future. Due to risk for malignant conversion, it is generally viewed as beneficial to treat patients who present with porokeratosis lesions. Our patient’s lesion ultimately cleared and he has not developed new lesions at 1-year follow-up.

Although DSAP generally presents in the third and fourth decades of life and porokeratosis of Mibelli during childhood, it is important to educate both dermatologists and primary care physicians to be aware of the possibility of both diagnoses in the elderly population.

The Diagnosis: Porokeratosis of Mibelli

There are 5 variants of porokeratosis: disseminated superficial actinic porokeratosis (DSAP), linear porokeratosis, porokeratosis of Mibelli, porokeratosis palmaris et plantaris disseminata, and punctate porokeratosis. The most common type is DSAP,¹ which is characterized by multiple lesions on the body, particularly in sun-exposed areas. The distinguishing feature of porokeratosis is the cornoid lamella, which is made up of parakeratotic cells extending through the stratum corneum. There also is a thin or absent granular layer beneath it (Figure).²

Patients generally present in the third and fourth decades of life.¹ Risk factors for porokeratosis include sun exposure, immunosuppression, and genetics.^2-4 Overexpression of the protein p53 in porokeratosis lesions has been demonstrated in studies investigating the genetics of porokeratosis.^5,6 A study of Chinese families with DSAP identified 3 different loci associated with DSAP: DSAP1, DSAP2, and DSAP3.² The progression to cancer has been noted in all types of porokeratosis lesions. Malignancies include squamous cell carcinoma, Bowen disease, and basal cell carcinoma.^7,8

Many treatments have been tried for DSAP including cryotherapy, topical 5-fluorouracil, photodynamic therapy, and topical imiquimod with varying success.¹ Our patient was treated with 
cryotherapy but had side effects from treatment including cellulitis and local infections with ulceration before finally healing.

Interestingly, our patient had a single lesion with pathology findings most consistent with DSAP at a later age. Although the pathology suggested DSAP, the size and solitary lesion was more consistent with porokeratosis of Mibelli. Porokeratosis of Mibelli can occur concurrently with DSAP,⁹ but we have not seen other lesions in this patient. We have educated our patient to be aware of other lesions that may occur in the future. Due to risk for malignant conversion, it is generally viewed as beneficial to treat patients who present with porokeratosis lesions. Our patient’s lesion ultimately cleared and he has not developed new lesions at 1-year follow-up.

Although DSAP generally presents in the third and fourth decades of life and porokeratosis of Mibelli during childhood, it is important to educate both dermatologists and primary care physicians to be aware of the possibility of both diagnoses in the elderly population.