Insect Bites

A 32-year-old man was worried about the recurring appearance of itchy red bumps on his feet and ankles.

Key point: Widely scattered, dome-shaped pruritic inflammatory papules, such as those illustrated, suggest insect bites. A biopsy showed mixed dermal infiltrate consisting of lymphocytes and eosinophils, consistent with an arthropod assault.

Treatment: Individual lesions resolved in a few days following applications of an ultrapotent topical corticosteroid ointment (halbetasol).

Note: While the bites themselves are easy enough to treat, the source should be investigated so that the problem will not continue. In this case, the bites were due to fleas that were infesting a family of possums living under the patient’s house. When the possums were caught and removed, the source of the insect infestation disappeared, as did the patient’s lesions!