Generalized lichen nitidus: a case report and review of the literature

Lichen nitidus, first described by Pinkus in 1907, is a rare skin disease of unknown aetiology [1, 2]. It is clinically characterized by the presence of multiple discrete papules that are tiny, shiny, and of varied colours. Most commonly, the lesions are localized on the neck, trunk, forearms, abdomen and the genitalia. However, infrequently cases with generalized skin involvement have been reported, mostly affecting children. Herein, we present a generalized form of lichen nitidus in a middle-aged woman, which has been successfully treated with aci-tretin. A 34-year-old woman was referred to the outpatient clinic of the Department of Dermatology due to the skin lesions, which have been observed for 2 years. Dermato-logical examination revealed thousand of shiny, polygonal, 1–2 mm sized papules located on the trunk, upper and lower limbs including palms (Figures 1 A–C). The papules did not show any tendency to coalesce (Figure 1 C). The face, neck, soles, and the genitalia were not affected. In the oral cavity, there were signs of whitening of the mucosa. Onychorrhexis was observed within the nails. The patient did not suffer from any concomitant disease. She did not use any drugs. Two skin biopsy samples from the thumb and trunk were taken for histopathological examination in order to confirm the clinical diagnosis (H + E) (Figure 2). Topical treatment with mild potent glucocorticoste-roids was initiated, but they proved to be ineffective. For this reason, a systemic treatment with methylpred-nisolone at an initial dose of 16 mg/day was introduced. A significant improvement after 2 months of therapy was observed, however the symptoms recurred while tapering the dose. As soon as histopathological confirmation of lichen nitidus in our department was made, acitretin at an initial dose of 50 mg/day was administered with good tolerance. The reduction of the skin lesions within 3–4 months was observed. At present, the patient takes the drug at a dose of 10 mg/day (6 months) showing marked improvement (she presents lesions only on her palms) and is being followed in the outpatient clinic. A typical clinical pattern of lichen nitidus is characterized by the presence of numerous shiny papules which may appear in a variety of shades, from fleshy pink to dark brown, whereas within dark skin they appear as light spots [3, 4]. The papules are 1–2 mm in diameter. Skin lesions are usually not accompanied by any additional symptoms with a sporadic exception of mild pruritus. …