Chigger

Chigger refers to the larval stage of certain mites in the family Trombiculidae. Chiggers are also known as harvest mites, harvest bugs, or berry bugs in some regions. They are very small, often about 0.3 to 0.5 millimeters, and can appear orange or red. The larvae are the only life stage that feeds on vertebrate hosts, including humans.

Life cycle and feeding behavior: Mites undergo egg, larval, nymphal, and adult stages. The six-legged larvae (chiggers) are parasitic, attaching to the skin of animals and feeding on skin cells and other tissue. They do not drink host blood. After feeding for several days, the larvae detach and molt into eight-legged nymphs and then adults. Only the larval stage is parasitic; adults and nymphs typically feed on detritus and other small organisms.

Clinical features: Chigger exposure commonly produces intensely itchy, red papules in exposed areas such as ankles, waist, groin, or folds of skin. The itching is often significant and may persist for days to weeks after the larvae drop off. The reaction is caused by the chigger’s digestive enzymes and the host’s inflammatory response to them, not by a bite introducing pathogens. Diagnosis is usually clinical, based on history of exposure and characteristic lesions.

Treatment and prevention: Management focuses on relieving itching and preventing secondary infection, using topical corticosteroids, oral antihistamines, and proper skin hygiene. Most cases resolve without specific antiparasitic treatment. Prevention includes avoiding known infested areas, using insect repellent containing DEET, treating clothing with permethrin, wearing long sleeves and pants, and washing clothing and gear promptly after outdoor exposure. Chiggers are distributed worldwide in warm climates, with higher incidence in grassy and wooded environments.