Manifestations of Localized Hypersensitivity in a Previously Sensitized Tissue

One of the consequences of introducing an antigen into the tissues of an animal is the induction of a specific hypersensitive state. The characteristics of this state are such that reexposure to the antigen, in amounts that are innocuous in the normal animal, produces in the sensitized animal a toxic and exaggerated inflammatory reaction. The specificity of the reaction is such that it can be induced only by the sensitizing antigen, by nonantigenic haptenic fragments of the antigen, or by substances serologically related to it. It is a well-documented observation that the eye, as an integral part of the body, participates in generalized systemic hypersensitivity reactions.¹This observation, however, fails to explain a specific local reaction of the eye in the absence of systemic allergic manifestations.²,³The idea of a local, selective tissue sensitization per se has been of great interest to ophthalmologists for many years, especially with