DOG HYPERSENSITIVITY IN ASTHMATIC CHILDREN

Abstract
The occurrence of dog hypersensitivity in 203 unselected asthmatic children was investigated by means of the skin prick test, the provocation test and RAST. The history of past and present exposure to dogs, symptoms in contact with dogs, and the effects of pet avoidance were examined. The amount of dog dander antigens was analyzed by counter‐immunoelectrophoresis from dust samples from 67 homes. A history of past or present dog hypersensitivity was obtained from 120 subjects (59%). A positive (≧++) prick test reaction was observed in 113 (56%), a positive provocation test result in 84 (41%) and a RAST class ≧ 1 in 140 (69%). The serum levels of IgE antibodies to dog dander correlated significantly with serum total IgE and the frequency of asthmatic attacks. The occurrence of dog allergy was not significantly associated with past or present exposure to dogs at home. However, the children who were exposed to dogs during the first year of life had dog allergy more often than those with late or without exposure. Significant amounts of dog dander antigen were also found in dust samples from homes where dogs have never been kept. Serum samples from previous years were available from 24 patients. Rising or steadily high levels of IgE antibodies to dog dander were observed even in subjects who strictly avoided dogs. The results show that dog hypersensitivity is an important cause of allergic disorders in asthmatic children, and that the common presence of dog dander antigens in our environment may induce dog allergy even without direct exposure to dogs.