User login
What is your diagnosis?
It most commonly affects young girls. The pathogenesis of LAHS is thought to involve a sporadic, autosomal dominant mutation that leads to a defect between the hair cuticle and the inner root sheath.1 This defect results in the hair being poorly anchored to the scalp, and therefore easily and painlessly plucked or lost during normal hair care.
The classic presentation of LAHS is that of hair thinning and hair that may be unruly and/or lackluster; the hair rarely, if ever, requires cutting.2 The key feature is the ability to easily and painlessly pluck hairs from the patient’s scalp. The affected area is limited to the scalp, and loss of eyebrows, eyelashes, and body hair should not be seen.
Diagnosis and consideration of the differential
The diagnosis of LAHS can in some cases be made on history and physical exam alone. Patients with LAHS typically will show hair thinning with or without dullness or unruliness. They lack evidence of scalp inflammation, such as erythema, scale, pruritus, and pain. Areas of hair thinning or aberration are typically not well demarcated, and there are typically not areas of complete hair loss. There is no scarring or atrophy of the scalp itself.
Diagnostic tests include the “hair pull test,” as well as trichogram testing. In the “hair pull test” a provider grasps a set of hair at the proximal shaft near the scalp. The traction applied should result in the painless and easy extraction of more than 10% of grasped hairs in a patient with LAHS. Removal of less than 10% of hair is a normal finding, as patients without LAHS typically have about 10% of their scalp hair in the telogen phase at any given time, which would result in removal during the hair pull test.3 In trichography, plucked hairs are examined under magnification, with or without the use of selective dyes. Cinnamaldehyde is a dye that stains citrulline, which is abundant in the inner root sheath, and can be a tool in identifying its presence and/or aberrations.4 A trichogram of the pulled hairs in a patient with LAHS may classically show ruffled appearance of the cuticle, misshapen anagen hair bulbs, and absence of the inner root sheath.5 Examination under magnification also allows providers to better identify telogen versus anagen hairs, which aids in the diagnosis. By carefully considering the patient history, physical exam, and results of additional hair tests, providers can make the diagnosis of LAHS and avoid unnecessary blood work and invasive procedures like scalp biopsies.
The differential diagnosis of hair loss frequently includes alopecia areata. However, in alopecia areata, patients typically have sharply demarcated areas of hair loss, which may involve the eyebrows, eyelids, and body hairs. In alopecia areata, providers may be able to identify the “exclamation point sign” in which the hair shaft thins proximally, leading to the appearance of more pigmented, thicker hairs floating above the scalp.
Telogen effluvium is a condition in which a medical illness or stress, such as systemic illness, surgery, severe emotional distress, childbirth, dietary changes, or another traumatic event, causes a disruption in the natural cycle of hair growth such that the percentage of hairs in the telogen phase increases from about 10% to up to 70%.6 Unlike in LAHS, in which shed hairs are in the anagen phase, the hair that is shed in telogen effluvium is in the telogen phase and will have a different appearance when magnified.
Anagen effluvium, loss of hairs in their growing phase, is typically associated with chemotherapy. The hairs become broken and fractured at the shaft leading to breakage at different points throughout the scalp. Affected areas can include the eyebrows, eyelashes, and body hair. In the absence of a history of administration of a chemotherapy agent (or other drug known to trigger hair loss), the diagnosis of anagen effluvium should not be made.
Patients with trichotillosis (also known as trichotillomania) present with areas of hair loss caused by intentional or subconscious hair pulling. It is considered a psychological condition that can be associated with obsessive compulsive disorder, although the presence of a secondary psychological diagnosis is not required. Providers may see irregular geometric shapes of hair loss, and on close inspection see broken hair shafts of different lengths. Patients most often pull hair from their scalps (over 70% of patients), but also can pull eyelashes, eyebrow hairs, and pubic hairs.7
Treatment
LAHS is self-limited and does not necessitate treatment. However, if patients or parents feel there is significant disease burden, perhaps with poor effects on quality of life or with psychosocial impairment, treatment with minoxidil 5% solution has been studied with some success reported in the literature.1,8,9
Ms. Natsis is a medical student at the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital-San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Ms. Natsis and Dr. Eichenfield had no relevant financial disclosures. Email them at pdnews@mdedge.com.
References
1. Arch Dermatol. 2002;138(4):501-6.
2. Int J Trichology. 2010;2(2):96-100.
3. Pediatric Dermatol. 2016:33(50):507-10.
4. Dermatol Clin. 1986;14:745-51.
5. Arch Dermatol. 2009;145(10):1123-8.
6. J Clin Diagn Res. 2015;9(9):WE01-3.
7. Am J Psychiatry. 2016;173(9):868-74.
8. Australas J Dermatol. 2018;59:e286-e287.
9. Pediatr Dermatol. 2014;31:389-90.
It most commonly affects young girls. The pathogenesis of LAHS is thought to involve a sporadic, autosomal dominant mutation that leads to a defect between the hair cuticle and the inner root sheath.1 This defect results in the hair being poorly anchored to the scalp, and therefore easily and painlessly plucked or lost during normal hair care.
The classic presentation of LAHS is that of hair thinning and hair that may be unruly and/or lackluster; the hair rarely, if ever, requires cutting.2 The key feature is the ability to easily and painlessly pluck hairs from the patient’s scalp. The affected area is limited to the scalp, and loss of eyebrows, eyelashes, and body hair should not be seen.
Diagnosis and consideration of the differential
The diagnosis of LAHS can in some cases be made on history and physical exam alone. Patients with LAHS typically will show hair thinning with or without dullness or unruliness. They lack evidence of scalp inflammation, such as erythema, scale, pruritus, and pain. Areas of hair thinning or aberration are typically not well demarcated, and there are typically not areas of complete hair loss. There is no scarring or atrophy of the scalp itself.
Diagnostic tests include the “hair pull test,” as well as trichogram testing. In the “hair pull test” a provider grasps a set of hair at the proximal shaft near the scalp. The traction applied should result in the painless and easy extraction of more than 10% of grasped hairs in a patient with LAHS. Removal of less than 10% of hair is a normal finding, as patients without LAHS typically have about 10% of their scalp hair in the telogen phase at any given time, which would result in removal during the hair pull test.3 In trichography, plucked hairs are examined under magnification, with or without the use of selective dyes. Cinnamaldehyde is a dye that stains citrulline, which is abundant in the inner root sheath, and can be a tool in identifying its presence and/or aberrations.4 A trichogram of the pulled hairs in a patient with LAHS may classically show ruffled appearance of the cuticle, misshapen anagen hair bulbs, and absence of the inner root sheath.5 Examination under magnification also allows providers to better identify telogen versus anagen hairs, which aids in the diagnosis. By carefully considering the patient history, physical exam, and results of additional hair tests, providers can make the diagnosis of LAHS and avoid unnecessary blood work and invasive procedures like scalp biopsies.
The differential diagnosis of hair loss frequently includes alopecia areata. However, in alopecia areata, patients typically have sharply demarcated areas of hair loss, which may involve the eyebrows, eyelids, and body hairs. In alopecia areata, providers may be able to identify the “exclamation point sign” in which the hair shaft thins proximally, leading to the appearance of more pigmented, thicker hairs floating above the scalp.
Telogen effluvium is a condition in which a medical illness or stress, such as systemic illness, surgery, severe emotional distress, childbirth, dietary changes, or another traumatic event, causes a disruption in the natural cycle of hair growth such that the percentage of hairs in the telogen phase increases from about 10% to up to 70%.6 Unlike in LAHS, in which shed hairs are in the anagen phase, the hair that is shed in telogen effluvium is in the telogen phase and will have a different appearance when magnified.
Anagen effluvium, loss of hairs in their growing phase, is typically associated with chemotherapy. The hairs become broken and fractured at the shaft leading to breakage at different points throughout the scalp. Affected areas can include the eyebrows, eyelashes, and body hair. In the absence of a history of administration of a chemotherapy agent (or other drug known to trigger hair loss), the diagnosis of anagen effluvium should not be made.
Patients with trichotillosis (also known as trichotillomania) present with areas of hair loss caused by intentional or subconscious hair pulling. It is considered a psychological condition that can be associated with obsessive compulsive disorder, although the presence of a secondary psychological diagnosis is not required. Providers may see irregular geometric shapes of hair loss, and on close inspection see broken hair shafts of different lengths. Patients most often pull hair from their scalps (over 70% of patients), but also can pull eyelashes, eyebrow hairs, and pubic hairs.7
Treatment
LAHS is self-limited and does not necessitate treatment. However, if patients or parents feel there is significant disease burden, perhaps with poor effects on quality of life or with psychosocial impairment, treatment with minoxidil 5% solution has been studied with some success reported in the literature.1,8,9
Ms. Natsis is a medical student at the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital-San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Ms. Natsis and Dr. Eichenfield had no relevant financial disclosures. Email them at pdnews@mdedge.com.
References
1. Arch Dermatol. 2002;138(4):501-6.
2. Int J Trichology. 2010;2(2):96-100.
3. Pediatric Dermatol. 2016:33(50):507-10.
4. Dermatol Clin. 1986;14:745-51.
5. Arch Dermatol. 2009;145(10):1123-8.
6. J Clin Diagn Res. 2015;9(9):WE01-3.
7. Am J Psychiatry. 2016;173(9):868-74.
8. Australas J Dermatol. 2018;59:e286-e287.
9. Pediatr Dermatol. 2014;31:389-90.
It most commonly affects young girls. The pathogenesis of LAHS is thought to involve a sporadic, autosomal dominant mutation that leads to a defect between the hair cuticle and the inner root sheath.1 This defect results in the hair being poorly anchored to the scalp, and therefore easily and painlessly plucked or lost during normal hair care.
The classic presentation of LAHS is that of hair thinning and hair that may be unruly and/or lackluster; the hair rarely, if ever, requires cutting.2 The key feature is the ability to easily and painlessly pluck hairs from the patient’s scalp. The affected area is limited to the scalp, and loss of eyebrows, eyelashes, and body hair should not be seen.
Diagnosis and consideration of the differential
The diagnosis of LAHS can in some cases be made on history and physical exam alone. Patients with LAHS typically will show hair thinning with or without dullness or unruliness. They lack evidence of scalp inflammation, such as erythema, scale, pruritus, and pain. Areas of hair thinning or aberration are typically not well demarcated, and there are typically not areas of complete hair loss. There is no scarring or atrophy of the scalp itself.
Diagnostic tests include the “hair pull test,” as well as trichogram testing. In the “hair pull test” a provider grasps a set of hair at the proximal shaft near the scalp. The traction applied should result in the painless and easy extraction of more than 10% of grasped hairs in a patient with LAHS. Removal of less than 10% of hair is a normal finding, as patients without LAHS typically have about 10% of their scalp hair in the telogen phase at any given time, which would result in removal during the hair pull test.3 In trichography, plucked hairs are examined under magnification, with or without the use of selective dyes. Cinnamaldehyde is a dye that stains citrulline, which is abundant in the inner root sheath, and can be a tool in identifying its presence and/or aberrations.4 A trichogram of the pulled hairs in a patient with LAHS may classically show ruffled appearance of the cuticle, misshapen anagen hair bulbs, and absence of the inner root sheath.5 Examination under magnification also allows providers to better identify telogen versus anagen hairs, which aids in the diagnosis. By carefully considering the patient history, physical exam, and results of additional hair tests, providers can make the diagnosis of LAHS and avoid unnecessary blood work and invasive procedures like scalp biopsies.
The differential diagnosis of hair loss frequently includes alopecia areata. However, in alopecia areata, patients typically have sharply demarcated areas of hair loss, which may involve the eyebrows, eyelids, and body hairs. In alopecia areata, providers may be able to identify the “exclamation point sign” in which the hair shaft thins proximally, leading to the appearance of more pigmented, thicker hairs floating above the scalp.
Telogen effluvium is a condition in which a medical illness or stress, such as systemic illness, surgery, severe emotional distress, childbirth, dietary changes, or another traumatic event, causes a disruption in the natural cycle of hair growth such that the percentage of hairs in the telogen phase increases from about 10% to up to 70%.6 Unlike in LAHS, in which shed hairs are in the anagen phase, the hair that is shed in telogen effluvium is in the telogen phase and will have a different appearance when magnified.
Anagen effluvium, loss of hairs in their growing phase, is typically associated with chemotherapy. The hairs become broken and fractured at the shaft leading to breakage at different points throughout the scalp. Affected areas can include the eyebrows, eyelashes, and body hair. In the absence of a history of administration of a chemotherapy agent (or other drug known to trigger hair loss), the diagnosis of anagen effluvium should not be made.
Patients with trichotillosis (also known as trichotillomania) present with areas of hair loss caused by intentional or subconscious hair pulling. It is considered a psychological condition that can be associated with obsessive compulsive disorder, although the presence of a secondary psychological diagnosis is not required. Providers may see irregular geometric shapes of hair loss, and on close inspection see broken hair shafts of different lengths. Patients most often pull hair from their scalps (over 70% of patients), but also can pull eyelashes, eyebrow hairs, and pubic hairs.7
Treatment
LAHS is self-limited and does not necessitate treatment. However, if patients or parents feel there is significant disease burden, perhaps with poor effects on quality of life or with psychosocial impairment, treatment with minoxidil 5% solution has been studied with some success reported in the literature.1,8,9
Ms. Natsis is a medical student at the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital-San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Ms. Natsis and Dr. Eichenfield had no relevant financial disclosures. Email them at pdnews@mdedge.com.
References
1. Arch Dermatol. 2002;138(4):501-6.
2. Int J Trichology. 2010;2(2):96-100.
3. Pediatric Dermatol. 2016:33(50):507-10.
4. Dermatol Clin. 1986;14:745-51.
5. Arch Dermatol. 2009;145(10):1123-8.
6. J Clin Diagn Res. 2015;9(9):WE01-3.
7. Am J Psychiatry. 2016;173(9):868-74.
8. Australas J Dermatol. 2018;59:e286-e287.
9. Pediatr Dermatol. 2014;31:389-90.
A 5-year-old female is brought to clinic for hair loss. The mother reports that when styling her daughter's hair, she has noticed areas of hair thinning, especially at the temples and at the occiput. The mother denies scale, pruritus, and erythema. The patient reports that her scalp does not hurt. She has never had a haircut because her hair hasn't grown long enough to cut. There is no history of specific bald spots. The patient has no personal history of psoriasis, seborrheic dermatitis, or autoimmune disease. No picking has been noted, and there is no history of compulsive behaviors or anxiety. The patient's mother has a history of Graves disease. The mother reports that the patient's older sister may have had hair thinning when she was younger as well, but no longer has thin hair.
The patient was previously seen by another provider who prescribed hydrocortisone 2.5% ointment, which the mother has been applying nightly without improvement.
The child is otherwise medically well and thriving, with no recent change in activity level and with growth parameters consistently around the 75th percentile for height and weight. On physical exam, the patient has blondish, fine hair with areas of poorly demarcated hair thinning at the left temple and at the occiput. The hair remaining at the occiput is normal in texture. There are no areas of complete hair loss. There is no scale, erythema, or abnormal pigmentation, and no cervical or occipital adenopathy. The patient has intact eyebrows and eyelashes.
What is your diagnosis?
Lichen nitidus, which literally means “shiny moss,” is a relatively rare, chronic skin eruption that is characterized clinically by asymptomatic, flat-topped, sharply-demarcated, skin-colored papules, which are sometimes described as being “pinpoint.”
Lichen nitidus mainly affects children and young adults. The most common sites of involvement are the trunk, flexor aspects of upper extremities, dorsal aspects of hands, and genitalia, but lesions can occur anywhere on the skin. The lesions also can develop in sites of trauma (Koebner phenomenon), and this can be a significant clinical clue to aid in the diagnosis of lichen nitidus in favor of other conditions which may present as many small papules.1 Nail changes can occur but are rare, presenting as dystrophy, pitting, riding, or loss of nail(s).2
Lichen nitidus can be a challenging diagnosis to make, especially if a practitioner is not used to seeing it. Many dermatologic conditions present with many fine papules, including the other answer choices in the given quiz question (molluscum contagiosum, keratosis pilaris, verruca vulgaris, papular eczema). What allows for a clearer diagnosis of lichen nitidus is the history provided by the patient as well as the exam. Lichen nitidus lesions typically arise without a known trigger and often persist for months while remaining asymptomatic.
Molluscum contagiosum tends to include papules that are larger and more substantial than lichen nitidus papules and may be accompanied by background hyperpigmentation or erythema, known as the “beginning of the end” sign. Keratosis pilaris is commonly thought of as a skin type more so than a skin condition, and is more commonly seen in fair-skinned individuals along the lateral arms and cheeks. It is commonly paired with a background of erythema and skin than tends to be more xerotic. Verruca are typically larger lesions, sometimes with a rough surface, and are not typically shiny. Verruca are more likely to present as a single lesion or a few lesions at a given location, as opposed to lichen nitidus which has many individual papules at a single location. Papular eczema typically is intensely pruritic and is associated with xerosis and atopy.
The cause of lichen nitidus is unknown, and there are no reported genetic factors that contribute to its presentation.3 It is thought to be a subtype of lichen planus, although this is still debated. There is more work that needs to be done to find answers to these questions and to assess what triggers these fine papules to present and in whom.
The dermatoscopic features of lichen nitidus were reported in a series of eight cases and include absent dermatoglyphics, radial ridges, ill-defined hypopigmentation, diffuse erythema, linear vessels within the lesion, and peripheral scaling.4 These features are distinctive in combination and can in some cases be used to clinically diagnose lichen nitidus without the need for a skin biopsy, which is an invasive procedure that should be avoided when possible, especially given the benign nature of lichen nitidus.
If a biopsy is performed, the histologic features that commonly are seen include well-circumscribed granuloma-like lymphohistiocytic infiltrates in the papillary dermis adjacent to ridges, mimicking a “ball-and-claw” formation.1,5
Lichen nitidus generally is self-limiting, with minimal cosmetic disruption; therefore, treatment usually is not necessary. The lesions typically resolve within 1 year of presentation – and often sooner. Topical steroids can be used for symptomatic relief of pruritus, but generally do not hasten resolution of the papules themselves. Additionally, there have been reports in the literature of the successful resolution of lesions using topical calcineurin inhibitors and UVB therapy.
In a case report of an 8-year-old child with histologically confirmed lichen nitidus that had been present for 2 years, pimecrolimus 1% cream was used twice daily for 2 months with improvement and flattening of the papules.6 This report is compelling because the lesions persisted for twice the expected time of resolution without improvement and then showed relatively quick response to pimecrolimus. In a case of a 32-year-old male with lichen nitidus on his penis, tacrolimus 0.1% was used for 4 weeks with resolution of the papules.7 Although given that lichen nitidus can self-resolve in this same time period, it is unclear in this case whether the tacrolimus was the independent cause of the resolution.
With regard to UVB therapy, there have been reports of lichen nitidus resolution after 17-30 irradiation sessions in patients with lesions present for 3-6 months, although again, it is possible that the resolution observed was simply the natural course of the lichen nitidus for these patients rather than a therapeutic benefit of UVB therapy.8,9
Given that lichen nitidus is benign and typically asymptomatic or with mild pruritus, it is reasonable to monitor the lesions without treating them. If the lesions persist beyond 1 year, it also is reasonable to trial therapies, such as topical calcineurin inhibitors and UVB therapy, although using these treatments earlier in the disease course has only limited supporting data and any improvement seen within 1 year of onset may be attributed to the natural disease course as opposed to an effect of the intervention. Considerations of the cost of therapy, as well as the degree to which the patient is bothered by the lesions and how long the lesions have persisted, should be undertaken when considering whether an intervention should be made.
Ms. Natsis is a medical student at the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. There are no conflicts of interest or financial disclosures for Ms. Natsis or Dr. Eichenfield. Email them at pdnews@mdedge.com.
References
1. Cutis. 1999 Aug 1;64(2):135-6.
2. J Am Acad Dermatol. 2004 Oct;51(4):606-24.
3. Papulosquamous diseases, in “Pediatric Dermatology,” 4th ed. (St Louis: Mosby; 2011, Vol. 2.
4. Pediatr Dermatol. 2018. doi: 10.1111/pde.13576.
5. Cutis. 2013 Dec;92(6):288, 297-8.
6. Dermatol Online J. 2011 Jul 15;17(7):11.
7. J Drugs Dermatol. 2004 Nov-Dec;3(6):683-4.
8. Int J Dermatol. 2004 Dec 23;45:615-7.
9. Photodermatol Photoimmunol Photomed. 2013 Aug;29(4):215-7.
Lichen nitidus, which literally means “shiny moss,” is a relatively rare, chronic skin eruption that is characterized clinically by asymptomatic, flat-topped, sharply-demarcated, skin-colored papules, which are sometimes described as being “pinpoint.”
Lichen nitidus mainly affects children and young adults. The most common sites of involvement are the trunk, flexor aspects of upper extremities, dorsal aspects of hands, and genitalia, but lesions can occur anywhere on the skin. The lesions also can develop in sites of trauma (Koebner phenomenon), and this can be a significant clinical clue to aid in the diagnosis of lichen nitidus in favor of other conditions which may present as many small papules.1 Nail changes can occur but are rare, presenting as dystrophy, pitting, riding, or loss of nail(s).2
Lichen nitidus can be a challenging diagnosis to make, especially if a practitioner is not used to seeing it. Many dermatologic conditions present with many fine papules, including the other answer choices in the given quiz question (molluscum contagiosum, keratosis pilaris, verruca vulgaris, papular eczema). What allows for a clearer diagnosis of lichen nitidus is the history provided by the patient as well as the exam. Lichen nitidus lesions typically arise without a known trigger and often persist for months while remaining asymptomatic.
Molluscum contagiosum tends to include papules that are larger and more substantial than lichen nitidus papules and may be accompanied by background hyperpigmentation or erythema, known as the “beginning of the end” sign. Keratosis pilaris is commonly thought of as a skin type more so than a skin condition, and is more commonly seen in fair-skinned individuals along the lateral arms and cheeks. It is commonly paired with a background of erythema and skin than tends to be more xerotic. Verruca are typically larger lesions, sometimes with a rough surface, and are not typically shiny. Verruca are more likely to present as a single lesion or a few lesions at a given location, as opposed to lichen nitidus which has many individual papules at a single location. Papular eczema typically is intensely pruritic and is associated with xerosis and atopy.
The cause of lichen nitidus is unknown, and there are no reported genetic factors that contribute to its presentation.3 It is thought to be a subtype of lichen planus, although this is still debated. There is more work that needs to be done to find answers to these questions and to assess what triggers these fine papules to present and in whom.
The dermatoscopic features of lichen nitidus were reported in a series of eight cases and include absent dermatoglyphics, radial ridges, ill-defined hypopigmentation, diffuse erythema, linear vessels within the lesion, and peripheral scaling.4 These features are distinctive in combination and can in some cases be used to clinically diagnose lichen nitidus without the need for a skin biopsy, which is an invasive procedure that should be avoided when possible, especially given the benign nature of lichen nitidus.
If a biopsy is performed, the histologic features that commonly are seen include well-circumscribed granuloma-like lymphohistiocytic infiltrates in the papillary dermis adjacent to ridges, mimicking a “ball-and-claw” formation.1,5
Lichen nitidus generally is self-limiting, with minimal cosmetic disruption; therefore, treatment usually is not necessary. The lesions typically resolve within 1 year of presentation – and often sooner. Topical steroids can be used for symptomatic relief of pruritus, but generally do not hasten resolution of the papules themselves. Additionally, there have been reports in the literature of the successful resolution of lesions using topical calcineurin inhibitors and UVB therapy.
In a case report of an 8-year-old child with histologically confirmed lichen nitidus that had been present for 2 years, pimecrolimus 1% cream was used twice daily for 2 months with improvement and flattening of the papules.6 This report is compelling because the lesions persisted for twice the expected time of resolution without improvement and then showed relatively quick response to pimecrolimus. In a case of a 32-year-old male with lichen nitidus on his penis, tacrolimus 0.1% was used for 4 weeks with resolution of the papules.7 Although given that lichen nitidus can self-resolve in this same time period, it is unclear in this case whether the tacrolimus was the independent cause of the resolution.
With regard to UVB therapy, there have been reports of lichen nitidus resolution after 17-30 irradiation sessions in patients with lesions present for 3-6 months, although again, it is possible that the resolution observed was simply the natural course of the lichen nitidus for these patients rather than a therapeutic benefit of UVB therapy.8,9
Given that lichen nitidus is benign and typically asymptomatic or with mild pruritus, it is reasonable to monitor the lesions without treating them. If the lesions persist beyond 1 year, it also is reasonable to trial therapies, such as topical calcineurin inhibitors and UVB therapy, although using these treatments earlier in the disease course has only limited supporting data and any improvement seen within 1 year of onset may be attributed to the natural disease course as opposed to an effect of the intervention. Considerations of the cost of therapy, as well as the degree to which the patient is bothered by the lesions and how long the lesions have persisted, should be undertaken when considering whether an intervention should be made.
Ms. Natsis is a medical student at the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. There are no conflicts of interest or financial disclosures for Ms. Natsis or Dr. Eichenfield. Email them at pdnews@mdedge.com.
References
1. Cutis. 1999 Aug 1;64(2):135-6.
2. J Am Acad Dermatol. 2004 Oct;51(4):606-24.
3. Papulosquamous diseases, in “Pediatric Dermatology,” 4th ed. (St Louis: Mosby; 2011, Vol. 2.
4. Pediatr Dermatol. 2018. doi: 10.1111/pde.13576.
5. Cutis. 2013 Dec;92(6):288, 297-8.
6. Dermatol Online J. 2011 Jul 15;17(7):11.
7. J Drugs Dermatol. 2004 Nov-Dec;3(6):683-4.
8. Int J Dermatol. 2004 Dec 23;45:615-7.
9. Photodermatol Photoimmunol Photomed. 2013 Aug;29(4):215-7.
Lichen nitidus, which literally means “shiny moss,” is a relatively rare, chronic skin eruption that is characterized clinically by asymptomatic, flat-topped, sharply-demarcated, skin-colored papules, which are sometimes described as being “pinpoint.”
Lichen nitidus mainly affects children and young adults. The most common sites of involvement are the trunk, flexor aspects of upper extremities, dorsal aspects of hands, and genitalia, but lesions can occur anywhere on the skin. The lesions also can develop in sites of trauma (Koebner phenomenon), and this can be a significant clinical clue to aid in the diagnosis of lichen nitidus in favor of other conditions which may present as many small papules.1 Nail changes can occur but are rare, presenting as dystrophy, pitting, riding, or loss of nail(s).2
Lichen nitidus can be a challenging diagnosis to make, especially if a practitioner is not used to seeing it. Many dermatologic conditions present with many fine papules, including the other answer choices in the given quiz question (molluscum contagiosum, keratosis pilaris, verruca vulgaris, papular eczema). What allows for a clearer diagnosis of lichen nitidus is the history provided by the patient as well as the exam. Lichen nitidus lesions typically arise without a known trigger and often persist for months while remaining asymptomatic.
Molluscum contagiosum tends to include papules that are larger and more substantial than lichen nitidus papules and may be accompanied by background hyperpigmentation or erythema, known as the “beginning of the end” sign. Keratosis pilaris is commonly thought of as a skin type more so than a skin condition, and is more commonly seen in fair-skinned individuals along the lateral arms and cheeks. It is commonly paired with a background of erythema and skin than tends to be more xerotic. Verruca are typically larger lesions, sometimes with a rough surface, and are not typically shiny. Verruca are more likely to present as a single lesion or a few lesions at a given location, as opposed to lichen nitidus which has many individual papules at a single location. Papular eczema typically is intensely pruritic and is associated with xerosis and atopy.
The cause of lichen nitidus is unknown, and there are no reported genetic factors that contribute to its presentation.3 It is thought to be a subtype of lichen planus, although this is still debated. There is more work that needs to be done to find answers to these questions and to assess what triggers these fine papules to present and in whom.
The dermatoscopic features of lichen nitidus were reported in a series of eight cases and include absent dermatoglyphics, radial ridges, ill-defined hypopigmentation, diffuse erythema, linear vessels within the lesion, and peripheral scaling.4 These features are distinctive in combination and can in some cases be used to clinically diagnose lichen nitidus without the need for a skin biopsy, which is an invasive procedure that should be avoided when possible, especially given the benign nature of lichen nitidus.
If a biopsy is performed, the histologic features that commonly are seen include well-circumscribed granuloma-like lymphohistiocytic infiltrates in the papillary dermis adjacent to ridges, mimicking a “ball-and-claw” formation.1,5
Lichen nitidus generally is self-limiting, with minimal cosmetic disruption; therefore, treatment usually is not necessary. The lesions typically resolve within 1 year of presentation – and often sooner. Topical steroids can be used for symptomatic relief of pruritus, but generally do not hasten resolution of the papules themselves. Additionally, there have been reports in the literature of the successful resolution of lesions using topical calcineurin inhibitors and UVB therapy.
In a case report of an 8-year-old child with histologically confirmed lichen nitidus that had been present for 2 years, pimecrolimus 1% cream was used twice daily for 2 months with improvement and flattening of the papules.6 This report is compelling because the lesions persisted for twice the expected time of resolution without improvement and then showed relatively quick response to pimecrolimus. In a case of a 32-year-old male with lichen nitidus on his penis, tacrolimus 0.1% was used for 4 weeks with resolution of the papules.7 Although given that lichen nitidus can self-resolve in this same time period, it is unclear in this case whether the tacrolimus was the independent cause of the resolution.
With regard to UVB therapy, there have been reports of lichen nitidus resolution after 17-30 irradiation sessions in patients with lesions present for 3-6 months, although again, it is possible that the resolution observed was simply the natural course of the lichen nitidus for these patients rather than a therapeutic benefit of UVB therapy.8,9
Given that lichen nitidus is benign and typically asymptomatic or with mild pruritus, it is reasonable to monitor the lesions without treating them. If the lesions persist beyond 1 year, it also is reasonable to trial therapies, such as topical calcineurin inhibitors and UVB therapy, although using these treatments earlier in the disease course has only limited supporting data and any improvement seen within 1 year of onset may be attributed to the natural disease course as opposed to an effect of the intervention. Considerations of the cost of therapy, as well as the degree to which the patient is bothered by the lesions and how long the lesions have persisted, should be undertaken when considering whether an intervention should be made.
Ms. Natsis is a medical student at the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. There are no conflicts of interest or financial disclosures for Ms. Natsis or Dr. Eichenfield. Email them at pdnews@mdedge.com.
References
1. Cutis. 1999 Aug 1;64(2):135-6.
2. J Am Acad Dermatol. 2004 Oct;51(4):606-24.
3. Papulosquamous diseases, in “Pediatric Dermatology,” 4th ed. (St Louis: Mosby; 2011, Vol. 2.
4. Pediatr Dermatol. 2018. doi: 10.1111/pde.13576.
5. Cutis. 2013 Dec;92(6):288, 297-8.
6. Dermatol Online J. 2011 Jul 15;17(7):11.
7. J Drugs Dermatol. 2004 Nov-Dec;3(6):683-4.
8. Int J Dermatol. 2004 Dec 23;45:615-7.
9. Photodermatol Photoimmunol Photomed. 2013 Aug;29(4):215-7.
