BLISTER BEETLES and Your Skin Health

There are about two hundred species of blister beetles found throughout the world. The beetle excretes a toxic substance called cantharidin from various parts of its body upon the slightest pressure or contact. Cantharidin applied to human skin, even in small amounts, will result in blister formation within a few hours. If the eyes are involved, severe reactions, even blindness, can occur. Blister beetles are active throughout the United States in the summer, but are more frequent in the west.

These beetles are from ~ to I inch in length. They are elongated creatures characterized by a "neck" that is distinctly narrower than the head or thorax. In the east the most common species is deep purple or black, while those found in the west are usually ash-colored.

Cantharidin has long been used as an aphrodisiac. The Lytta vesicatorea species, found in Europe and especially in Spain, is known as the "Spanish fly." If taken internally, cantharidin can cause severe nausea, vomiting, diarrhea, and cramps. It is sometimes used to treat warts because of its ability to blister the skin.

Most blisters result from contact with the beetles when they are drawn to artificial lighting in the evening. If the beetle is permitted to walk across the skin, cantharidin is not released. If the insect is gently brushed off, however, the fluid will probably be secreted and blistering will result. There may be a slight tingling or burning sensation within a few minutes. Mild redness follows; blisters begin to appear in two to three hours, and are fully formed in eight to ten hours. They are large and often linear.

Treatment for BLISTER BEETLES
These blisters may be treated as bum blisters. Simple protection suffices for most. Cool soaks are cleansing and soothing. Large blisters may be drained and protected with dressings and an antibiotic ointment.

Prevention Tips for BLISTER BEETLES
Blister beetles should be gently blown off the skin, never crushed. Yellow bulbs for outdoor lighting are less attractive to them.