A baffling bullous eruption in the antecubital fossae of military personnel had occurred during several summers in South Vietnam. Appearing first after a night's sleep in the field, large blisters, subsequent severe skin necrosis, and prolonged disability were characteristic.
An insect repellent diethyl toluamide (DEET), was shown experimentally to produce an eruption identical to the cases of antecubital blistering seen clinically.
DEET may, therefore, be the cause of some of the clinical cases, although a vesicating insect previously had been thought wholly the culprit. The repellent DEET is too effective to be removed from military use but it should be used with caution and not applied in the antecubital and popliteal fossae.
Lamberg SI, Mulrennan JA. Bullous Reaction to Diethyl Toluamide (DEET)Resembling a Blistering Insect Eruption. Arch Dermatol. 1969;100(5):582-586. doi:10.1001/archderm.1969.01610290066013