Erythema nodosum is a skin lesion that usually appears as red or purplish-red subcutaneous nodules, commonly seen in young women in spring and autumn. There are two main clinical categories, usually idiopathic erythema nodosum can be cured by most patients, while secondary erythema nodosum can be cured only after symptomatic treatment of the primary disease. 1. idiopathic erythema nodosum: most patients can be cured by themselves, and usually the rash will gradually fade away without scarring in 3-6 weeks after the attack. However, there are a few patients with chronic course of erythema nodosum, and the course of the disease can last for several months or years. If you want erythema nodosum to heal itself, you can increase physical exercise, enhance physical fitness, eat more nutritious food, such as eggs, milk and soy products with high protein content, and supplement vitamin C and vitamin E, so that erythema nodosum can heal itself as soon as possible; 2.Secondary erythema nodosum: most of this kind of erythema nodosum cannot heal itself, and symptomatic treatment should be carried out for the primary disease, so that erythema nodosum can be healed. The erythema nodosum can only be cured after the treatment of the primary disease. For those secondary to infectious factors, such as erythema nodosum caused by tuberculosis infection, anti-tuberculosis treatment is needed before the erythema nodosum can subside. For those secondary to inflammatory diseases such as leukoaraiosis and systemic lupus erythematosus, glucocorticoid immunosuppressants such as prednisone, methylprednisolone and dexamethasone should be applied to treat the primary diseases before erythema nodosum can gradually improve. Erythema nodosum is only a kind of skin damage, usually rarely involving the internal organ system, and most of them have good prognosis. However, patients should find the cause of the disease in time and carry out the treatment for the cause. In addition, patients should rest properly during acute attacks and avoid standing and walking for a long time.