If allergic reaction occurs when using metronidazole, you need to stop using metronidazole immediately and relieve the symptoms by applying medication and life care. 1. Medications: If symptoms such as itching, redness, swelling and pimples appear, you should choose medications such as loratadine tablets, cetirizine tablets and hydrocortisone tablets under the guidance of a doctor, and you can use topical glycerine lotion to alleviate the allergic reaction. If the allergic reaction is serious and anaphylactic shock occurs, it is necessary to consult a doctor immediately and take symptomatic treatment under the doctor’s guidance, such as oxygen inhalation, injection of adrenal hormone, etc., and replenish body fluids appropriately. 2. Life care: pay attention to rest, balanced nutrition, eat more fruits and vegetables, drink more water, promote metabolism, appropriate exercise, enhance physical fitness. The application of metronidazole allergy, the need to avoid using the drug again in the future, the use of medication under the guidance of a doctor, do not self-medication, in order to avoid the adverse effects of the body, affecting health.