The role of IgE-mediated hypersensitivity in the development of middle ear disease has not been completely resolved. However, on the basis of our investigations and those of other laboratories, we suggest that approximately two thirds of patients with chronic recurrent otitis media do not have allergies. The other third may have allergic rhinitis, and this allergic rhinitis could play a direct role in producing eustachian tube dysfunction in recurrent otitis media. However, viral infections of the upper respiratory tract may also induce IgE-mediated release of mast cell inflammatory mediators, and could cause otitis media on the basis of viral infection alone. Subtle immunologic deficiencies involving the IgG2 subclass and other immunoglobulin subclasses may also be lower in otitis-prone children, and this may be a genetically inherited disorder. Finally, the possibility of food allergy in otitis media must be considered, particularly in the young otitis-prone child with chronic recurrent otitis media.