A distinctive erythematous macular exanthem of the adult: a new entity?
BACKGROUND: Delineating a new exanthem is difficult. Atypical or modified types of already known conditions can easily be mistaken for new entities. OBJECTIVES: To report 29 cases of an acute, self-limiting exanthem never described before. METHODS: Clinical description, serology, polymerase chain reaction (PCR) and other laboratory investigations. RESULTS: The eruption starts with bright pink-red slightly oedematous macules symmetrically arranged on the trunk. The lesions tend to coalesce, and spread to the limbs on which they may acquire a marginated annular appearance. The lesions invariably spare the face (including oral mucous membranes), palms and soles. The eruption is pruritic and lasts 20-30 days, clearing spontaneously. The disease has a predilection for men aged 17-56 years and occurs mostly between spring and summer. Serological tests, PCR assays and investigations for bacteria, parasites or viruses were consistently negative. CONCLUSIONS: The clinical picture does not recall any of the classical exanthems or their atypical forms.