Cantharidin - Spanish fly and blister beetles

• vesicant (blistering agent) synthesized by over 1500 species of beetles (members of the order Coleoptera)
• these beetles, affectionately known as 'blister beetles', come in an array of pretty colours, don't bite or sting, and are found all over the world
• male beetles produce and utilize cantharidin as a defence mechanism to avoid being eaten and stuff, while female beetles receive it from males for the same reason that female humans receive a nice dinner and jewelry from males: in hopes of getting laid
• contact with catharidin or the beetle itself produces a vesiculobullous (features both vesicles and bullae) skin disease that manifests within hours of exposure
• apparently blowing a beetle off rather than brushing it off will reduce the severity of a resulting skin reaction
• absorbed into the lipid (fat) component of skin cell membranes, where it activates neutral serine proteases, which are enzymes that go about breaking down other proteins, leading to degeneration of desmosomes, which help to anchor cells together
• the ultimate result is blistering within the layers of the epidermis, which usually heals without scarring
• has been shown to be a vasoconstrictor and positive inotrope in cardiac tissue in vitro, suggesting that less toxic derivatives might make good heart drugs
• has been employed historically as an aphrodisiac and an abortifacient
• is the primary active ingredient in Spanish fly, a purported aphrodisiac made by grinding up a bunch of dried out blister beetles
• whole dried beetles, called mylabris, are utilized in Chinese traditional medicine to treat a whole bunch of things
• its so-called aphrodisiac effects are likely related to its ability to produce skin irritation, which can provide extended stimulation of the necessary, uh, tissues to produce arousal
• cantharidin also irritates the genital tract, mimicking arousal
• employed as a 0.7% solution (applied topically) to treat warts and molluscum contagiosum (both of which are viral skin infections that are gross, can easily spread, and can be sexually transmitted)
• unsurprisingly, cases of poisoning are generally due to the ingestion for aphrodisiac purposes as opposed to topical administration for medical purposes and can feature such severe symptoms as coagulopathy, seizures, renal failure, and death
• for more information about terminology, it can be helpful to consult an online medical dictionary or other Internet resources such as legitimate library or medical reference sites
• the Internet also can be used to locate a doctor or purchase diabetes supplies
  

- Moed L, Shwayder TA, Chang MW. Cantharidin revisited: a blistering defense of an ancient medicine. Arch Dermatol. 2001 Oct;137(10):1357-60. Review.