[Palmoplantar lichen nitidus: a rare cause of palmoplantar hyperkeratosis].

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.