The most important thing in the treatment of allergic dermatitis is to find the allergen, remove the cause, and treat the rash appropriately (immediate treatment, medication, etc.) depending on the rash, which can lead to a rapid recovery. Finding the allergen is critical in the treatment of allergic dermatitis and requires the patient to recall the contact that may have caused the allergy one to two weeks prior to the appearance of the rash. When the cause is unknown or when it is difficult to distinguish which substance is responsible for the allergy, a patch test can be used to find the cause. When re-exposed to the same allergen, rinse off the contact immediately with water, etc. Medication for allergic dermatitis is divided into topical and internal medications. Topical medications include: glycolate lotion (for mild redness, papules, blisters and no exudate), 3% boric acid solution (for acute dermatitis with more exudate), zinc oxide oil (for acute dermatitis with little redness, blisters and exudate), etc. Internal medications include: internal antihistamines, vitamin C, intravenous 10% calcium gluconate injection, internal or intravenous glucocorticoids (for short-term use in patients with severe pancytopenia), etc. After cure, re-exposure to allergens may still lead to re-occurrence, and care should be taken to avoid known allergens to avoid recurrence.