Case for diagnosis

Frey, Marcos Noronha; Bonamigo, Renan Rangel; Luzzatto, Laura; Machado, Raquel Bozzetto; Seidel, Gabriela Bestani

doi:10.1590/S0365-05962010000400023

Abstracts

Lichen nitidus is a rare dermatosis, characterized by round, skin-colored papules whose size varies between 1-2 mm and are generally asymptomatic. It does not have predilection for gender or race, affecting mainly children and young adults. Its clinical course is unpredictable, but most cases tend to spontaneously regress years after the onset of the disease. Lesions are often localized, but rare reports of disseminated disease exist.

Lichen nitidus; Lichenoid eruptions; Lichens

Líquen nítido é uma dermatose rara, caracterizada por pápulas arredondadas normocrômicas de diâmetro, variando entre 1-2 mm, e geralmente assintomáticas. Sem predileção por sexo ou raça, acomete, principalmente, crianças e adultos jovens, na maioria dos casos, possuindo curso clínico imprevisível e tendendo à regressão espontânea, anos após o início da doença. As lesões são em geral localizadas, mas raros relatos da doença cursando com lesões disseminadas existem.

Erupções liquenóides; Líquen nítidos; Líquens

WHAT IS YOUR DIAGNOSIS?

^IM.D.; Specialization in Dermatology (in progress) at the Health Sciences Federal University of Porto Alegre (UFCSPA) - Porto Alegre (RS), Brazil

^IIPh.D. in Medical Sciences from the Federal University of Rio Grande do Sul (UFRGS); Professor (Ph.D.) of Dermatology at the Health Sciences Federal University of Porto Alegre (UFCSPA) and Professor of the Postgraduate Program in Pathology at the Health Sciences Federal University of Porto Alegre (UFCSPA) - Porto Alegre (RS), Brazil

^IIIPathologist Physician; M.S. from the European Institute of Oncology; Specialization in pathological anatomy from the Porto Alegre Clinical Hospital (HCPA) - Porto Alegre (RS), Brazil

^IVM.D. - Specialization in Dermatology from the Health Sciences Federal University of Porto Alegre (UFCSPA) - Porto Alegre (RS), Brazil

^VM.D. - Specialization in Internal Medicine from the General Hospital of Caxias do Sul - Caxias do Sul (RS), Brazil

Mailing address

ABSTRACT

Lichen nitidus is a rare dermatosis, characterized by round, skin-colored papules whose size varies between 1-2 mm and are generally asymptomatic. It does not have predilection for gender or race, affecting mainly children and young adults. Its clinical course is unpredictable, but most cases tend to spontaneously regress years after the onset of the disease. Lesions are often localized, but rare reports of disseminated disease exist.

Keywords: Lichen nitidus; Lichenoid eruptions; Lichens

HISTORY OF THE DISEASE

Male patient, seven-years-old, with a history of discrete pruriginous skin lesions for 18 months. Lesions first appeared on his forearms and rapidly disseminated. The patient denied the use of previous medication, comorbidities or familial history of skin lesions. Physical examination revealed small, nonscaly, smooth and shiny skin-colored papules, with 1-2 mm of diameter, affecting nearly all his skin, sparing only nails, palmoplantar regions, mucous membranes, and part of his hair scalp (Figures 1, 2).

Histopathological evaluation showed the presence of dense lymphohistiocytic dermal infiltrate, partially surrounded by interpapillary cones, atrophic superadjacent epidermis, and parakeratosis (Figures 3 and 4). Culture was negative for acid-fast bacilli (BAAR) and fungi.

COMMENTARIES

Described for the first time in 1901 by Pinkus ^1,2 as a variant of lichen planus, and once treated as a tuberculosis lesion due to its granulomatous histopathologic aspect, lichen nitidus is a rare, chronic idiopathic dermatosis that affects mainly children and young adults. It is characterized by multiple circumscribed monomorphic papules, skin-colored and shiny, whose diameter varies between 1-2 mm and are often asymptomatic (some patients report pruritus). There is no predilection for sex or race and its clinical course is unpredictable. Most cases tend to spontaneously regress years after the onset of the disease. It is often localized, rarely disseminated, affects mostly the genital region, upper extremities, thorax and abdomen. ^1-10 Occasionally, palmoplantar, oral and nail lesions (thickening, linear striations, pittings, and roughness) can be observed. ^5,7-10 There are atypical forms of the disease, described as keratodermic, follicular, vesicular, hemorrhagic, petechiae or perforating; ^5,7-10 Köebner's phenomenon can also be found. ^1,2,4,5,7

The histopathology of this dermatosis is fairly typical, described as a lymphohistiocytic dermal infiltrate, sharply demarcated and round, surrounded by hyperplastic dermal pappilae (classically known as the "ball and clay" infiltrate), and parakeratosis with epidermal atrophy right above the infiltrate. ^1-5,7-10 Degenerative alterations of the basement layer, identical to those found in lichen planus lesions, may be seen, but contrary to lichen planus, direct immunofluorescence on lichen nitidus does not usually reveal immunoglobulin or complement deposits. ^1,7

Although clinically and histologically distinct, lesions of lichen nitidus and lichen planus may coexist in the same patient (in about 30% of the cases of lichen nitidus), and the possibility that lichen nitidus is a clinical variant of lichen planus has never been completely dismissed. ^2,4,5,7-9

Differential diagnosis should be done especially when lichenoid-like or follicular lesions are present, with emphasis on lichen planus, lichen striatus and lichen spinolosus. The following also deserve special attention: keratosis pilaris, lichen amyloidosis, phrynoderma, follicular mucinosis, secondary amyloid syphilis, Darier's disease, pytiriasis rubra pilaris, and psoriasis. ^2,3,5-7

Since lichen nitidus is a localized, asymptomatic disease that tends to remit, the objective of treatment in most cases is to alleviate the symptoms. The disseminated form of the disease has a more unpredictable clinical course, oftentimes longer. Currently, there is no consensus about the best treatment option. ^1-10 In addition to antihistamines, topical and systemic corticosteroids, retinoids, cyclosporine, tuberculostatic drugs, itraconazole, dihydrochlorobenzene and ultra-violet A and B phototherapy are treatment alternatives found in the literature. ^1,2,4-10

REFERENCES

1. Santos OLR, Neves RG. Líquen nítido extenso. An Bras Dermatol. 1994;69:235-40.
2. Shiohara T, Kano Y. Lichen planus and lichenoid dermatoses. In: Bolognia JL, Jorizzo JL, Rapini RP, editors. Dermatology. Spain: Mosby Elsevier; 2008. p. 172-4.
3. Lernia V, Piana S, Ricci C. Lichen planus appering subsequent to generalized lichen nitidus in a child. Pediatr Dermatol. 2007;24:453-55.
4. Al-Mutairi N, Hassanein A, Nour-Eldin O, Arun J. Generalized lichen nitidus. Pediatr Dermatol. 2005;22:158-60.
5. Tilly JJ, Drolet BA, Esterly NB. Liquenoid eruptions in children. J Am Acad Dermatol. 2004;51:606-12.
6. Soroush V, Gurevtch A, Peng S. Generalized lichen nitidus: case report and literature review. Cutis. 1999;64:135-6.
7. Torres-Segura M, Pimentel MIF, Ramos-e-Silva M. Líquen nítido. Folha Médica. 1993;106:135-8.
8. Sysa-Jedrzejowska A, Wozniacka A, Robak E, Waszczykowska E. Generalized lichen nitidus: a case report. Cutis. 1996;58:170-2.
9. Ocampo J, Torné R. Generalized lichen nitidus report of two cases treated with astemizol. Int J Dermatol. 1989;28:49-51.
10. Arizaga A, Bang R. Generalized lichen nitidus. Clin Dermatol. 2002;27:115-17.