Abstract
To study the skin reactions induced by black fly bites, a questionnaire survey was carried out on 736 patients. Forty-four patients (6.0%) experienced a large cutaneous reaction more than 5cm in diameter, which was evaluated as a result of allergic reaction. There was no significant difference in the frequency of large cutaneous reaction by black fly bites between cases with and without allergic disease. Large cutaneous hypersensitivity was observed more frequently in the residents of Katsuyama and Okayama than in those of Misasa and Kurayoshi. On the contrary, reduced skin reaction after repeated bites was observed more frequently in the residents of Misasa and Kurayoshi than in those of Katsuyama and Okayama.
