Skin Parasites

While the parasites we've looked at so far are found all over the world, the chigoe flea, or jigger, lives mostly in Central and South America. It lives on the ground and feeds on humans and other mammals, mostly attacking the feet. The chigoe is different from other fleas in that it burrows under the skin to feed on blood and lay eggs. Unlike the scabies mite, it doesn't go completely under the skin. Instead, the chigoe digs a hole and inserts its head under the skin. Its respiratory organs and back legs stay outside the body so it can breathe while feeding. The chigoe also lays its eggs through the opening, which fall to the ground. Soon afterwards, it dies, but the eggs hatch into adults within a couple of days.

A chigoe bite looks like a small red dot with a black center -- the rest of the chigoe's body -- surrounded by a ring of white. A chigoe flea infection is known as tungiasis [source: Collins]. It causes skin inflammation, itching and pain. Even once the chigoe dies and falls off, the open lesion left behind is prone to infection and abscesses. Multiple chigoe bites, which are common among people who become infected, can lead to more severe conditions like gangrene and blood infections.

Because chigoes are partially visible on the skin, they're usually easy to diagnose. They can be removed with tweezers (with great care to avoid leaving the head under the skin) or suffocated and killed on the skin's surface with oil or petroleum jelly. Doctors often prescribe antibiotics to treat the infections. One of the most effective ways to ward off chigoes is to wear closed-toed shoes, but pesticides are also used.

In the next section, we'll look at an internal parasite that gets others to do its dirty work: the botfly.