BACKGROUND: Eggs are among the foods most frequently causing allergy. Hen eggs are the most important. Those of other birds are of lesser significance. OBJECTIVE: We report an unusual case of food allergy after consumption of eggs from duck and goose in an adult patient without hen egg allergy. METHODS: Skin prick tests were performed with fresh white and yolk from eggs of duck and goose and egg white, egg yolk, ovalbumin, and ovomucoid from hen egg. Specific serum IgE was measured to hen egg proteins. SDS-PAGE and IgE immunoblotting were carried out with egg white extracts from hen, duck, and goose. RESULTS: Skin tests were positive to egg whites from duck and goose. The skin tests and specific serum IgE were negative to hen egg proteins. Immunoblotting demonstrated the presence of specific IgE to a proteic band of molecular weight around 45 kd. CONCLUSIONS: We report a patient with an IgE-mediated allergy to egg white from duck and goose without hen egg allergy. Ovalbumin seems to be the responsible protein. The antigenic determinant of this protein seems to be specific of order Anseriforme and it is not present in the ovalbumin of order Galliforme.
BACKGROUND: Eggs are among the foods most frequently causing allergy. Hen eggs are the most important. Those of other birds are of lesser significance. OBJECTIVE: We report an unusual case of food allergy after consumption of eggs from duck and goose in an adult patient without hen egg allergy. METHODS: Skin prick tests were performed with fresh white and yolk from eggs of duck and goose and egg white, egg yolk, ovalbumin, and ovomucoid from hen egg. Specific serum IgE was measured to hen egg proteins. SDS-PAGE and IgE immunoblotting were carried out with egg white extracts from hen, duck, and goose. RESULTS: Skin tests were positive to egg whites from duck and goose. The skin tests and specific serum IgE were negative to hen egg proteins. Immunoblotting demonstrated the presence of specific IgE to a proteic band of molecular weight around 45 kd. CONCLUSIONS: We report a patient with an IgE-mediated allergy to egg white from duck and goose without hen egg allergy. Ovalbumin seems to be the responsible protein. The antigenic determinant of this protein seems to be specific of order Anseriforme and it is not present in the ovalbumin of order Galliforme.