Erythema nodosum is an inflammatory condition that occurs in the subcutaneous fat and can be treated with anti-inflammatory medications. The cause of erythema nodosum is not well understood, but it has been found that it may be related to infections, especially with hemolytic streptococcus. Most patients with erythema nodosum have symptoms of upper respiratory tract infection such as fever, weakness and muscle aches before the onset of rash. Therefore, in terms of treatment, if there are symptoms of infection, sensitive antibiotics such as penicillin, cephalosporin, levofloxacin, etc., and proprietary Chinese medicines, such as Pudilan Anti-inflammatory Oral Liquid, Naked Flower ZiZhu Tablet, and QingHeYeDiDiYu Capsule can be taken, and pain is obvious, and antipyretic and analgesic drugs, such as painkillers can be added, such as painkilling tablets, Ibuprofen granules, severe cases can be given oral glucocorticoids.