A small pimple in the armpit may be folliculitis, soft fibroma, enlarged lymph nodes and other diseases. After the cause is clear, the cause should be dealt with, and if there is a primary disease, the primary disease should be actively treated. 1. Folliculitis: there are rich sweat glands and small sweat glands in the armpit, if you do not pay attention to hygiene, folliculitis is very easy to occur. Acne caused by folliculitis may have redness, swelling, heat and pain and other inflammatory manifestations, and can be treated with topical antibiotics (such as fusidic acid cream, etc.) to promote recovery. 2. Soft fibroma: a small pimple in the armpit, if it is a tiny, protruding pimple without pain, it may also be soft fibroma, which can be treated by laser. 3. Enlarged lymph nodes: a small acne in the armpit may also be an enlarged lymph node, mostly suggesting that the surrounding organs or tissues have inflammation or cancer (such as lymph node inflammation, mastitis, breast cancer, etc.), and should be promptly consulted to improve the examination and make a clear diagnosis. A small pimple in the armpit may also be caused by other reasons, and it is recommended that the patient consult a doctor in time for a clear diagnosis. Drugs need to be used under the guidance of a doctor.