Egg protein sensitization in patients with bird feather allergy.

We have studied the hypersensitivity to hen's egg protein and chicken meat in 25 adults with a previous diagnosis of bronchial asthma and rhinoconjunctivitis due to bird feather sensitization. Seventeen of the 25 reported good tolerance to the ingestion of egg and chicken meat. The skin tests were negative to both antigens in 15 of them, and positive for egg in two. All 17 patients had negative RAST to chicken meat and egg protein. The remaining eight patients had intolerance to egg, and three of them also to chicken meat ingestion; in seven of the eight cases allergic to egg, the alimentary intolerance began after the clinical symptoms of bird feather sensitization. In all eight cases the skin tests were positive to egg yolk, and in five of them also to egg white and chicken meat. These patients evidenced specific serum IgE antibodies to egg yolk, four of them to egg white, and seven to chicken meat. These results demonstrate the high frequency (32%) of the association of sensitization to egg proteins, particularly egg yolk, in a selected population of patients with known allergy to bird feathers, thus suggesting that in some patients feather sensitization could trigger or somehow facilitate the later sensitization to egg yolk proteins.