Immunotherapy in allergy to dog. Immunologic and clinical findings of a double-blind study.

Twenty-seven dog-allergic asthmatic children with no pets in the home were included in the study. The clinical trial was performed as a double-blind study using a commercial standardized aluminum hydroxide-bound dog dander and hair extract or histamine-placebo. The patients were randomized into the active treatment or the placebo group on the basis of the RAST (e5) and the provocation test with aqueous dog dander and hair extract. The good clinical response of immunotherapy with dog dander and hair extract has been reported earlier. The specific immunotherapy resulted in an increase in the serum level of antigen-specific IgG antibodies (P less than .01) and a decrease in the skin sensitivity to dog extract (P less than .001) in the active treatment group when compared with the placebo group. The treatment was well-tolerated. No systemic reactions occurred and local reactions were mild. The results show a good immunologic response with a standardized dog dander and hair extract. There were no major changes in the course of bronchial asthma in either group. After 1 year of immunotherapy the subjects had no symptoms on a dog-exposure of short duration. This must be carefully emphasized when considering the indications for immunotherapy.