Back-of-the-ear pimples are common and usually form when oil, sweat, and dead skin build up in the folds behind the ear. Since this area doesn’t get washed as often or as thoroughly as the face, pores can clog easily. Things like wearing headphones, hats, or having long hair rubbing on the skin can also trap bacteria and trigger breakouts.

These pimples can feel sore because the skin behind the ear is thin and sensitive. Touching the area frequently, sweating, or not cleaning earrings can make the irritation worse. Sometimes, using heavy hair products can also contribute, as oils transfer to the skin and block the pores.

To treat them, keep the area clean by washing behind the ears daily with warm water and a gentle cleanser. Avoid picking the pimple, as it can cause infection. You can dab a small amount of acne treatment—like benzoyl peroxide or salicylic acid—on the spot to help reduce inflammation. Keeping headphones, glasses, and pillowcases clean will also prevent new breakouts.

If the pimples become very painful, swollen, or turn into hard lumps that don’t go away, it may be a cyst, and seeing a doctor or dermatologist is a good idea.