A growth on the back that hurts when touched may be caused by folliculitis, boils, sebaceous cysts secondary infection and other factors. It is recommended to pay attention to local care, give topical or oral antibiotic treatment, if necessary, through surgical treatment. 1. Folliculitis: poor hygiene, high temperature, sweating, scratching leads to skin breakage, Staphylococcus aureus infection, resulting in inflammation of hair follicles. Inflammatory factors stimulate the nerves, resulting in localized redness, swelling and pain. Mupirocin ointment and fusidic acid cream can be given to apply topically, and oral amoxicillin and cefadroxil can be taken to fight infection if necessary. 2. Boils: usually caused by Staphylococcus aureus invading individual hair follicles and surrounding tissues, resulting in localized suppurative lesions. It can be treated by applying topical ichthyol ointment and mupirocin ointment, together with oral amoxicillin and other drugs. Surgical incision and drainage is required when abscesses are formed. 3. Sebaceous cysts secondary infection: sebaceous cysts are caused by sebaceous gland ducts blocked, secretions in the local collection. Sebaceous cysts are usually painless, but can be painful if combined with infection. It can be treated with topical ichthyol ointment, together with oral cephalosporin, cefuroxime and other drugs. After infection control, it can be treated by surgical removal. A lump on the back, a touch of pain, it is recommended to go to the hospital dermatology department in a timely manner, first to clarify the cause, and then for the cause of the treatment, the use of drugs need to be used under the guidance of a doctor.