[Allergic reaction form of middle ear mucosa. An animal experiment study]

The middle ear is not a body site at which anaphylactic reactions (type I in the classification of Coombs and Gell) predominate. Non-IgE-mediated reactions preferentially occur in response to an allergen. Out of 64 guinea pigs, 48 were sensitized and provoked with an allergen (p-toluene-diamine, hair dye). Sixteen nonsensitized animals were treated in order to rule out toxic reactions. A mainly lymphomonocytic infiltration (without eosinophilia) is proof of allergic origin. In addition there is a more or less pronounced edema. This may also be absent, as the present study shows. A differential diagnosis of inflammatory reactions is not feasible with conventional histologic techniques alone. This is doubtless due to the fact that immune mechanisms (tuberculin reaction type) are also present in chronic infections. In the animal experimental model, a definitive separation between toxic and allergic reactions is possible. Sporadic clinical observations of this allergic reaction form of the middle-ear mucosa are thus confirmed.