text: To know the histochemical effects of steroid treatment on eosinophil accumulation in nasal polyps of AIA and the histochemical feature of a recurring polyp and to detect distributional differences between storage and secreted forms of eosinophil cationic proteins, we carried out immunocytochemical labelling with antibodies against EGI (recognizing resting and activated eosinophils) and EG2 (recognizing only activated eosinophils), and determined eosinophil infiltration in nasal polyps that were obtained before and after steroid treatment, and at recurrence of polyps.