A small bump behind the ear may be a boil, acne, epidermoid cyst, keloid, etc., which can be improved by medication, surgery, laser and other treatments. 1. Boils: Localized bacterial infection of the skin behind the ears may cause localized boils, resulting in the appearance of small bumps behind the ears, accompanied by localized redness, swelling, heat and pain and other localized symptoms, such patients can use penicillin, cefuroxime and other antibiotics to help treat the treatment, but also according to drug sensitivity tests to select antibiotics for treatment. 2. Acne: Generally speaking, acne occurs on the face, chest and back and other seborrheic areas, but it may also involve behind the ears, scalp and other special areas, such patients can use topical retinoic acid cream, benzoyl peroxide, fusidate ointment and other ointments for local application, and in severe cases, it can be combined with oral isotretinoin or tetracycline-based drugs for treatment. 3. Epidermoid cysts: If a small bump behind the ear is caused by an epidermoid cyst, the lesion can usually be seen on the surface of the bump a small black spot, usually using local surgical excision to help treatment, with better results. 4. Keloid: after ear piercing, ear trauma, etc. may form a local scar behind the ear, resulting in a small pimple behind the ear, such patients can use laser treatment, surgical excision, local injections and other methods to remove the local keloid. It should be noted that the above treatments need to be carried out under the guidance of a physician to avoid the occurrence of adverse reactions.