A small flesh grain growing in the armpit hurts, consider and folliculitis, sebaceous cysts and other factors related to, can be given topical drugs, taking drugs, surgical intervention and other methods of treatment. 1. Folliculitis: Folliculitis is a purulent inflammation confined to the mouth of the hair follicle. It is mostly caused by coagulase-positive Staphylococcus aureus infection, and is most common in the head, face, neck, buttocks and vulva. The lesions start as red follicular papules, pustules appear in the center within a few days, surrounded by a red halo, and can be treated with topical mupirocin or fusidic acid as prescribed by the doctor. 2. Sebaceous cysts: these are retention cysts formed due to the blockage of sebaceous gland ducts in the skin and the gradual accumulation of sebum. The cause of pain may be related to local infection, need to follow the doctor’s advice to choose drugs to fight infection, such as cefixime, etc., if necessary, feasible surgical excision. There may be other reasons for the pain in the armpit, the patient can go to the hospital, under the guidance of the doctor to improve the examination, and give the corresponding treatment and therapy.