Azelaic acid is called azelaic acid cream over the counter. Azelaic acid cream is a dermatologic agent. It has antibacterial activity against Propionibacterium acnes and Staphylococcus epidermidis, which may be based on the principle of inhibiting protein synthesis of microorganisms, and is used for the topical treatment of mild and moderate inflammatory acne vulgaris. Adverse reactions to azelaic acid cream include itching, burning, irritation, tingling sensation, erythema, dry skin, rash, flaking, dermatitis and contact dermatitis in individual patients at the initial stage of administration. Very few reports have caused exacerbation of asthma, decreased skin pigmentation, leukoplakia, hirsutism, signs of follicular keratosis and worsening of recurrent herpes labialis. It is contraindicated for those who are sensitive to any of the ingredients in this product. During the use of the drug patients should pay attention to a light diet, do not stay up late, do not eat spicy and greasy food, pay attention to facial or skin hygiene. The drug should be used under the guidance of a doctor, the initial dosage should not be too large, do not add other drugs on their own to prevent adverse reactions and drug interactions.