Chiggers are tiny mites that attach themselves to the skin to feed on skin cells. It is only the larvae (babies) of the chigger that bite people. When a chigger bites you, it attaches tiny mouth parts to the skin, usually near a skin pore or hair follicle. Then it injects some saliva (spit) into the skin. The saliva has an enzyme that breaks down skin cells into a liquid. To prevent the saliva from spreading, the skin cells around the saliva harden.
This creates a tube called a stylostome. The young chigger sucks in the liquid through the stylostome. It is the stylostome that causes the redness, swelling, and severe itching. In North America, chigger bites do not transmit disease. But they do cause significant itching as the bite heals. This may take a week or longer.
Chiggers are found in certain outdoor areas, such as berry patches, tall grass and weeds, and woodland edges.
Chiggers bite humans around the waist, ankles, or in warm skin folds. Bites commonly occur in the summer and fall months.
The main symptoms are:
- Severe itching
- Red pimple-like bumps or hives
Itching usually occurs several hours after the chiggers attach to the skin. The bite is painless.
A skin rash may appear on the parts of the body that were exposed to the sun. It may stop where the underwear meets the legs. This is often a clue that the rash is due to chigger bites.
Exams and Tests
A doctor can diagnose chiggers by examining the rash.
The goal of treatment is to stop the itching. Antihistamines and corticosteroid creams or lotions may be helpful.
Secondary infection may occur from scratching.