Trombiculosis (Q100828)

A pruritic, papular or papulovesicular skin eruption due to bites by the larvae of trombiculid mites (harvest mites or chiggers). The larva injects digestive enzymes into the skin in order to facilitate feeding from host tissue. The cutaneous response is considered to be due both to an irritant effect of the larval saliva and an acquired hypersensitivity to salivary antigens. Areas favoured by the mites are those where the skin is thin (genital region, axillae, limb flexures).