BACKGROUND: Lichen nitidus is a rare condition, which may be a cause of palmoplantar hyperkeratosis. We report two cases. CASE REPORTS: A 53 year-old woman presented with a dry and fissured palmoplantar hyperkeratosis. Histological examination of a biopsy showed the typical features of lichen nitidus. Significant improvement was obtained with acitretin. A few months later, multiple lichen nitidus papules appeared on the limbs and the abdomen. A 67 year-old woman was referred to us for a fissured, disabling palmoplantar hyperkeratosis refractory to topical steroids. Histological examination led to the diagnosis of lichen nitidus. Local PUVA therapy resulted in the cleaning of her lesions. Later, typical papules of lichen nitidus appeared on her elbows. DISCUSSION: Nineteen cases of palmoplantar localization of lichen nitidus have been described. The features are usually tiny yellow papules but sometimes a non-specific keratoderma resembling chronic eczema. Palmoplantar involvement of lichen nitidus may be isolated or associated with cutaneous lesions on unusual sites. Oral retinoids and local PUVA are effective treatments.

Purpuric generalized lichen nitidus: an unusual eruption simulating pigmented purpuric dermatosis.Dermatology. 2004;208(2):167-70.

BACKGROUND: Generalized haemorrhagic lichen nitidus is rare. To our knowledge, this form of presentation has only been reported once. OBJECTIVE: To describe a new case of generalized haemorrhagic lichen nitidus simulating a pigmented purpuric dermatosis. METHODS AND RESULTS: We document a 24-year-old man who presented with an 8-month history of a progressive non-pruritic, red-brown papular eruption on the dorsa of the feet, ankles and distal third of the legs. A diagnosis of Schamberg's progressive pigmentary dermatosis was made, and no treatment was prescribed. Two months later, the lesions had extended to the abdomen, groins, forearms, elbows and wrists. Biopsy of the skin of the right foot revealed lesions typical of lichen nitidus with subepidermal extravasation of red cells and capillary wall hyalinization. Macrophages and T lymphocytes were abundant in the infiltrate. CONCLUSION: Purpuric generalized lichen nitidus should be included in the differential diagnosis of pigmented purpuric dermatoses.