IgE, IgG1, and IgG4 antibodies in egg allergy were evaluated. It was found that there was a correlation between clinical egg sensitivity and IgE RAST from birth to 5 years of age, although IgG1 and IgG4 antibodies tended to increase with age in egg-allergic subjects. The role of IgG subclass antibodies in this allergic disorder is also discussed.