By Martha A. Simpson, D.O., M.B.A.
Assistant Professor of Family Medicine
Ohio University College of Osteopathic Medicine

CHIGGER BITES EXTREMELY ITCHY, BUT USUALLY BETTER IN TEN DAYS

Question: My husband and I have been bothered with chiggers. We have tried everything for the itching – alcohol, peroxide, sprays, lotions, nail polish and cream from the doctor. This has been going on for about four months. Nothing has helped. They seem to be spreading. What can be done?

Answer: First let me describe what chiggers are, why they cause itching, how to get rid of the itch, and how to prevent chigger bites. Then you and you doctor can decide if what you have are really chigger bites.

Chiggers are very small – actually, microscopic – insects in the mite family. They are classified in the same arachnid family as spiders and are closely related to ticks. It is the immature or larval form of the mite that does the biting. Interestingly, after they feast on animals, including humans, they mature and then eat only the eggs of certain other insects.

Chiggers do not burrow under the skin, as is commonly believed. Rather, when chigger larvae bite, they insert a specialized mouth part into a skin pore or hair follicle, which injects saliva into the skin. This dissolves the skin cells into a liquid that the chigger can drink through a tubelike structure formed when the saliva makes contact with and hardens surrounding tissue. This structure, called a stylostome, acts like a drinking straw. It is the stylostome that causes the itching, irritation and characteristic red welt to form. The itching, which can be quite severe, usually peaks at about two days after the bite, and the stylostome is destroyed by your body in about 10 days.

Chiggers are found in grassy places, in thick brush and in areas with heavy vegetation and limited sunshine. They are temperature sensitive and are most active when the ground temperature is between 77 and 86 degrees. They become inactive in temperatures below 60 degrees.

Prevention is the key to managing chiggers. Wear clothing that prevents chiggers from making contact with your skin. Long sleeved shirts, tightly woven socks and clothes, pants tucked inside of boot tops, and buttoned cuffs will all reduce chigger bites. Most mosquito repellants will fend off chiggers, too, so it’s good idea to use these products when you go into fields or woods or if you plan to sit on the grass. Remember to reapply it every few hours since repellants only last a few hours.

After you return from any potentional exposure, a hot bath with lots of soap and scrubbing will wash many chiggers off before they have a chance to bite. Once you have been bitten, over-the-counter creams with benzocaine or camphor-phenol can help reduce the itching.

It’s also a good idea to wash potentially chigger-infested clothes in hot, soapy water. Unlaundered clothes or clothes washed in cool water will allow chiggers to survive and have another chance to bite you. If you are camping or otherwise unable to wash your clothes in hot water, lay them out in hot sunshine. This will help kill any chiggers that may still be lurking in your clothes.

Unless you keep getting re-infested with chiggers, it seems unlikely to me that you would still be itching from chiggers after four months. You and your husband need to see your physician for a reevaluation of your rashes. What you have may not be chiggers at all.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.