Chronic pruritic dermatitis in asthmatic monkeys: a subhuman primate analogue of atopic dermatitis?

In a group of adult normal rhesus monkeys and monkeys with IgE-mediated asthma observed over a period of 15 years, 2 of the latter group were found to have chronic, generalized pruritus and dermatitis. The skin lesions were recurrent and located on the flexural surfaces of the forearms leading to the thickened, scaling, lichenified dermatitis in that area in the skin of 1 monkey. The pruritus and skin lesions subsided following therapy with depot methylprednisolone but recurred after this therapy was discontinued. Both animals had recurrent severe cutaneous infections in excoriated lesions following scratching without infections in other organs. The cutaneous infections responded to penicillin therapy but recurred with scratching. No deficiencies in immunoglobulin levels, or lymphocyte responses to phytohemagglutinin were found in these 2 monkeys. The 2 animals differed from normal animals by their high titers of immediate skin reactivity to ascaris antigen, persistent and severe asthmatic responses to ascaris antigen, high IgG antibody levels to ascaris antigen but all of the latter findings were also present in asthmatic monkeys without dermatitis. Cutaneous biopsies of lesions were nonspecific but provided no evidence for other explanations for the dermatitis which appears to be an analogue of human atopic dermatitis.