By Gary M. White, MD
Chiggers are a type of mite that can bite human skin causing very itchy bumps. Other names for chiggers are harvest mite, harvest bug, harvest lice and redbugs. The term chigger refers to the larval stage as this is the only stage which bites humans.
The adult lays eggs on leaves, blades of grass or the ground. Since they like humidity, forests, grassy areas, gardens and moist soil near bodies of water are preferred. Once the eggs hatch and the larvae mature, they seek an acceptable host to feed, e.g. turtle, toad, bird, small mammal or a human. Once attached, they can travel extensively on the skin. Once they find an ideal place to feed, e.g., thin epidermis, they bite, inject fluid and suck lymph fluid and broken down tissue [Cutis 2017;99;386]. The body reacts to the injury and foreign material and an itchy bump results.
Grouped, extremely itchy red papules most commonly on the legs and waistline is characteristic. Summer penile syndrome is where a male is bitten in the groin area by chiggers and develops swelling, itching and trouble urinating.
The lesions resolve within 1-2 weeks. A potent topical steroid may be given.
Chiggers are most common in the Southeastern US. They like moist, shady areas with thick vegetation. When hiking, avoid those areas or at a minimum stay on the trail and avoid brushing up against plants. Wear long sleeves and long pants that can be tucked into your socks or shoes. Use insect or tick repellent, especially around the tops of your shoes, shirt neck, cuffs, and waistband. Shower as soon as you go indoors. Wash your clothes in hot water.