[Palmoplantar lichen nitidus: a rare cause of palmoplantar hyperkeratosis]. / Lichen nitidus palmoplantaire. Une cause rare de kératodermie palmoplantaire.

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.

[Cold-induced urticaria]. / Urticaire au froid.

Cold urticaria is characterized by the development of urticaria, usually superficial and/or angioedematous reaction after cold contact. It was found predominantly in young women. The diagnosis is based on the history and ice cube test. Patients with a negative ice cube test may have represented systemic cold urticaria (atypical acquired cold urticaria) induced by general body cooling. The pathogenesis is poorly understood. Cold urticaria can be classified into acquired and familial disorders, with an autosomal dominant inheritance. Idiopathic cold urticaria is most common type but the research of a cryopathy is necessary. Therapy is often difficult. It is essential that the patient be warned of the dangers of swimming in cold water because systemic hypotension can occur. H1 antihistamines can be used for treatment of cold urticaria but the clinical responses are highly variable. The combination with an H2 antagonists is more effective. Doxepin may be useful in the treatment. Leukotriene receptor antagonists may be a novel, promising drug entity. In patients who do not respond to previous treatments, induction of cold tolerance may be tried.