Metronidazole Gel and Azelaic Acid need to be staggered and used separately in the morning and evening to avoid adverse reactions. Metronidazole gel is used to treat inflammatory papules, impetigo, rosacea red acid, azelaic acid is used to treat common acne. Both are more irritating to the skin when used together and may damage the skin, so it is recommended to use them separately in the morning and evening. The skin is prone to tingling sensation when using the two types of drugs for the first time, it is recommended that patients use one type of drug first and observe whether there is any adverse reaction on the skin, if the discomfort is acceptable, wait until it subsides for a period of time, then use the other type of drug. If the discomfort on the skin is very obvious, you need to use a lot of water to rinse to relieve, if the skin tolerated later, that is, you can use the drug normally. The application of metronidazole gel and azelaic acid may cause local skin itching, burning and other adverse reactions, it is recommended to use the drug under the guidance of a doctor, not blindly self-medication to avoid adverse effects.