CUTANEOUS REACTIVITY TO MOSQUITO BITES AND ITS ANTIGENS IN CATS

This study describes 26 cats with mosquito bite hypersensitivity. Most were short-haired, free-roaming cats. Typical clinical features were seasonal (summer), symmetric miliary dermatitis on the pinnae. Mosquit o bite exposure with Aedes albopictus was performed on the pinnae and the lateral thorax in five cases and three healthy cats. All sites sho wed weals within 20 min. Papules, which revealed eosinophilic dermatit is, were recognized during a 12-48-h period. The control cats showed o nly slight and transient erythema after being bitten. Intradermal skin tests with an extract of A. albopictus were performed in three cases, and Prausnitz-Kustner tests under A. albopictus bites were performed in three cases. Both tests showed weals in all cases studied, although papules were not observed. Intradermal skin tests with the control ca ts, and Prausnitz-Kustner tests with saline and healthy cat serum fail ed to produce any positive reactions. The findings indicate that mosqu ito bite hypersensitivity in cats is triggered by a type I hypersensit ivity reaction to mosquito antigens. Certain other factors may be invo lved in the formation of delayed papular reactions. Whether this is a normal or abnormal reaction to mosquito bites is also discussed.