Eosinophil leukocytic response in dinitrochlorobenzene skin hypersensitivity reaction in the chicken.

The cutaneous inflammation evoked by topical application of dinitrochlorobenzene in sensitised chickens was studied at 24- and 48-hours post-challenge. A slight increase in vascular permeability was present at 24 hours but absent at 48 hours. Histologically, the reaction comprised oedema and a diffuse infiltration of polymorphonuclear granulocytes in the superficial dermis, and intense perivascular mononuclear infiltrations in the deep dermis. The apparent participation of eosinophils was a noteworthy feature of the reaction.