Blister beetle dermatitis
Blister beetle dermatitis is a cutaneous condition that occurs after contact with any of several types of beetles, including those from the Meloidae and Oedemeridae families. Blister beetles secrete an irritant called cantharidin, a vesicant that can get onto humans if they touch the beetles.
The term "blister beetle dermatitis" is also occasionally and inappropriately used as a synonym for Paederus dermatitis, a somewhat different dermatitis caused by contact with pederin, an irritant in the hemolymph of a different group of beetles, the rove beetles.