[Chondrodermatitis nodularis helicis: epidermal hyperplasia with transepithelial elimination (author's transl)]

CNH strongly resembles, both clinically and histopathologically, other lesions showing transepithelial elimination. WE studied 14 cases, only one of which was a woman. Ths lesions had either a smooth surface or a scaly one. Histological findings were rather poor in the smooth lesions; the scaly lesions, instead, which were more advanced, showed epidermal proliferation and perforation, dermal acidophilic necrosis, transepithelial elimination, granulation tissue, and perichondritis. Actinic elastic degeneration seemed to be the first alteration; it was present in all. This, together with the repeated adverse climatic factors and the fact that circulation is of the terminal type in the region affected, is followed by the acidophilic necrosis between the apex of the cartilage and the epidermis. The processes which take place in both cartilage and epidermis are secondary to the dermal lesion. The former perforates and this is followed by elimination of the altered tissues. Persistence of the lesion is to be ascribed to the fact that the diseased cartilage can not be eliminated completely. CNH is the most frequent of the conditions which show transepithelial elimination. It is less frequent in women because they protect themselves from adverse climatic factors by covering their ears with their hair.