Hard knots under the skin are usually caused by folliculitis, neurofibroma, etc. Folliculitis can be eliminated by medication, and fibroma can be eliminated by surgical treatment. 1. Folliculitis: folliculitis is generally caused by bacterial infection caused by purulent inflammation, which will lead to some damage to the subcutaneous tissue, resulting in the symptoms of hard knots under the skin, you can take amoxicillin, cephradine and other drugs under the guidance of a doctor, with antibacterial and anti-inflammatory effect, can relieve the patient’s hard knots under the skin, allergy to drugs is prohibited. 2. Fibroma: Neurofibroma is a kind of autosomal hereditary disease, usually caused by the loss of tumor inhibition, which may lead to hard nodules under the skin, and can be operated under the guidance of the doctor. It is recommended that patients go to the hospital in time for examination and treatment, and always observe the physical condition.