Chronic dermatitis may be caused by chronic diseases, eczema, etc. Depending on the cause of the disease, the treatments include medication, surgical treatment and food therapy. 1. Chronic dermatitis caused by chronic diseases: some patients are due to diabetes or uremia and other chronic dermatitis, need to be actively treated under the guidance of the doctor to treat the original disease. Diabetic patients need to inject insulin to control blood sugar, uremia patients need to take furosemide and other diuretics or dialysis treatment. 2. Chronic dermatitis caused by eczema: need to take antihistamines such as loratadine, external hormone ointment symptomatic treatment, some patients with hypertrophic mossy skin changes, need to go to the dermatology department for liquid nitrogen cryotherapy. It is necessary to avoid contact with related allergens, at the same time, avoid spicy, less alcohol, eat more food rich in vitamins, trace elements and protein. The medication should follow the doctor’s instructions.