Chigger bites typically take one to three weeks to clear up, according to Healthline. During that time, small red blisters or bumps form clusters on the skin, causing itchiness and irritation. Treating the bumps with ice and anti-itch topical creams, such as calamine lotion or hydrocortisone, discourages scratching.
When humans come in contact with chiggers, these tiny, red mites cling to the skin and inject saliva that converts cells to liquid, Healthline states. The surrounding skin tissue hardens into a feeding tube, allowing chiggers to stay attached and consume dissolved cells for long periods.
Chiggers prefer to bite areas where skin is moist and thin, such as the groin, wrinkle folds and the back of the knee. Humans usually notice symptoms within one to three hours of a bite and experience the most severe itching during the first two days, according to MedicineNet.