Dermatitis includes contact dermatitis, insect bite dermatitis, allergic dermatitis, etc. If the symptoms are mild, it can usually be cured by itself in about 1 week. If the symptoms are severe and recurring, it can not be cured by itself, and it needs to be treated, and it can usually be cured in 1 to 3 weeks after treatment. 1. Contact dermatitis: contact dermatitis may be caused when patients are exposed to irritating substances. If the symptoms are mild and the area of breakage is small, it can usually heal itself in about 1 week. If there are blisters, vesicles and other symptoms, you need to take glucocorticosteroids such as prednisone under the guidance of a doctor, and at the same time, topical glycerine lotion to relieve the local itching and other symptoms, it takes 1 to 3 weeks to be cured. 2. Insect bite dermatitis: when patients are bitten by mosquitoes, insect bite dermatitis may occur. If it is a mosquito bite, usually about 1 week can be self-cured. If it is a wasp, scorpion and other bites, it usually takes about 2 weeks to heal itself. Patients should not scratch the affected area to avoid worsening of the disease. 3. Allergic dermatitis: Allergic dermatitis may occur due to the patient’s exposure to allergens. If the symptoms are mild and the contact with allergens is stopped, the disease can be cured in about 1 week. However, if the allergens are more difficult to find and recurring, anti-allergy drugs such as loratadine and chlorpheniramine can be taken under the guidance of a doctor, and can usually be cured in about 2 weeks. When the patient develops dermatitis, it is recommended to consult a doctor in time for diagnosis and treatment by a professional doctor.