Ectoparasite Bites

Intensely pruritic lesions of acute onset are evident on the legs of a 24-year-old woman who had no history of similar episodes. She was in excellent health and took no medications. She had spent the previous evening seated outdoors at a restaurant. Physical examination showed many indurated wheals (A), some of which had an obvious central punctum (B) consistent with insect bites. The temporal relationship of the rash to a potential exposure to insects or arthropods (such as chiggers or various plant mites), along with an absence of lesions in areas covered by clothing, strongly suggested that ectoparasite bites were responsible.

The patient was treated with 5-mg levocetirizine dihydrochloride daily for a week and desoximetasone 0.05% gel to apply to individual lesions once or twice daily. The patient reported relief on the following day.