Evaluation of skin test for chromoblastomycosis using antigens prepared from culture filtrates of Fonsecaea pedrosoi, Phialophora verrucosa, Wangiella dermatitidis and Exophiala jeanselmei.

Antigenic substances were prepared from culture filtrates of Fonsecaea pedrosoi, Phialophora verrucosa, Wangiella dermatitidis and Exophiala jeanselmei. These antigenic substances were evaluated for detecting cutaneous delayed hypersensitivity in rats experimentally-infected with F. pedrosoi, P. verrucosa. W. dermatitidis, E. jeanselmei, Cladosporium carrionii and Fonsecaea compactum and in patients with chromoblastomycosis caused by F. pedrosoi. The F. pedrosoi antigen elicited positive reactions in all of the animals infected with F. pedrosoi and in 5 of 6 patients. The P. verrucosa, W. dermatitidis and E. jeanselmei antigens elicited positive reactions in all of the animals infected with the homologous species. These antigens displayed cross-reactivity in some of the animals and patients, whereas more than half of them exhibited positive reactions only to the antigens prepared from the homologous species. These results suggest that a delayed-type skin test using the antigens prepared by the authors may be useful not only for the diagnosis of chromoblastomycosis but also for the identification of species of the causative agent.