Oil beetle dermatitisT63.4

Toxic, possibly blistery dermatitis caused by contact with the oil beetle (Meloidae), triggered by the cantharidine produced by the beetle.

Oil beetles (there are about 210 species in Europe) live especially in warm areas, in dry regions, especially on flowers, leaves or on the ground.

When in danger, oil beetles produce an oily liquid containing the highly toxic cantharidine from pores in the leg joints. Cantharidin is only synthesized by the male beetles. The oil beetle poison protects the animals from natural enemies such as ants and ground beetles. Cantharidine is a strong toxin that causes severe toxic dermatitis on the skin, possibly with blisters and necroses, even after brief contact. The drug (known as "Spanish fly" - actually synonymous with the beetle Lytta vesicatoria) is said to have an erectile-enhancing effect in small doses. In oral doses of 0.03g the poison is already lethal. Dried beetle extracts were formerly used for medical purposes (rheumatic complaints), for the production of the cantharid patch.

Toxic dermatitis at the contact points.

Cantharis vesicatoria globules are used in homoeopathy for itchy or painful dermatoses: 5 globules every 2 hours. They are also used for other indications (cystitis, gastrointestinal problems, etc.).

Compare also the "Paederus dermatitis" caused by short-winged beetles, in which beetles from the family Staphylinidae release the toxin "pederin", which is comparable to cantharidine in its mode of action.

1. López López D et al (2016) Safety and effectiveness of cantharidine podophylotoxin salicylic acid in the treatment of recalcitrant plantar warts. Dermatol Ther doi: 10.1111/dth.12356.
2. Torbeck R et al (2014) Cantharidine: a comprehensive review of the clinical literature. Dermatol Online J 20. pii:13030/qt45r512w0.
3. v. Stebut E (2015) Oil beetle. In travel dermatoses E.v.Stebut (Hrsg) Springer -Verlag Berlin-Heidelberg S 236.