Acne aestivalis. A histopathological study.

Twelve histological sections with the diagnosis acne aestivalis (Mallorca acne) were revised and compared with the clinical diagnosis. Two histological diagnosis were wrong, one being folliculitis necroticans the other an uncharacteristic follicular disease. Non the less this patient had clinical acne aestivalis. In five patients accordance was found between histopathology and the clinical picture. Among the last five patients with histological acne aestivalis one had clinical rosacea, one yersinosis and dermatitis herpetiformis, one acne vulgaris, one miliaria or transcient acantholytic dermatosis, and the last one folliculitis perforans. The two last mentioned patients had the same histological picture which could be consistent with folliculitis perforans. The similarity in histopathology in this disease and acne aestivalis is emphasized. The histopathology in acne aestivalis could indicate, that the disease starts as a damage in corium and that the changes in the pilosebaceous apparatus are secondary.