Clinical and histopathologic correlation of midge bites

Many species of files viciously bite humans and animals. I had the opportunity to observe such bites by the gnat Leptoconops torrens during a recent epidemic that occurred in an inland desert area of California. The bite may produce an urticarial wheal, but, more characteristically, it induces formation of a hard, indolent, pruritic papule. In biopsy specimens taken within three days after the bite, the superficial infiltrate was composed or lymphocytes and histiocytes, while eosinophils were the preponderant cell found in the deeper dermis and subcutaneous fat. These clinical and histopathologic findings are similar to those reported for the bite of the blackfly, Simulium.