Got Chiggers? It Figures!

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Published on: Jun. 2, 2000

Last revision: Nov. 5, 2010

chigger larvae the advantage of something to press against to attach themselves. Imagine a little chigger pushing its back or legs against the elastic of your shorts to help it pierce your skin. Imagine also how many points of leverage might be provided for hungry larvae by a single pair of support hose.

Chigger larvae also push against opposing flesh, which helps explain why bites tend to occur more frequently in the underarms, between the thighs, at the backs of knees and in elbow crooks. Chiggers also find it easier to attach where skin is thinner, not leathered by exposure. Some of these sensitive areas are difficult to scratch in public.

Most chigger larvae feed at the site of a hair follicle or pore. Chiggers don't sting like bees or suck blood like mosquitos or ticks, rather they scrape or puncture the skin with bladelike mouthparts, called chelicerae. Once a chigger has an opening, it injects saliva, which contains proteolytic enzymes, to liquify the tissue so it can ingest it.

Our immune system walls off the area where the chigger has injected its saliva, forming a narrow, hardened tube, called a stylostome, through which the chigger feeds, as if through a straw. If nothing interrupts its meal, it will feed for three to four days before dropping off.

Chiggers don't burrow into the skin. Some swelling may slightly envelop a chigger, but the chigger remains on the outside, and all it takes is a slight scratching to remove it. A scratched off chigger will not bite again.

Because most of us respond to chigger saliva with itching and scratching, we do not make good hosts for the larvae. They more successfully feed on reptiles, including lizards, snakes and turtles, or birds or small mammals. But, too hungry or opportunistic or not schooled enough to be fastidious, chigger larvae will attempt to nourish themselves on human flesh.

After tromping around outdoors, you may be able to feel chiggers crawling over your skin or attempting to attach themselves. That's a subtle warning to take action to remove them. Many more chiggers roam over us than ever bite. Chiggers usually come in droves, so it's possible to have dozens, hundreds or even thousands on our bodies at one time.

Our normal movements and hygiene, along with the difficulty the larvae have gaining a mouthhold on us, keep most chiggers from successfully attaching, but people have reported hundreds of bites resulting

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