Erythema all over the body after drinking alcohol is mainly caused by allergy, i.e. alcoholic erythema, which is mainly caused by food or drink containing ethanol. It is believed that erythema after drinking is mainly due to allergy to certain chemical components in ethanol, or allergy to yeasts in barley or alcoholic beverages in ethanol, thus causing microvascular dilatation of the skin and mucous membranes. The main manifestation is erythema on the trunk a few hours after drinking alcohol, which may be accompanied by conjunctival congestion, allergic rhinitis, and flushing and congestion of the mucous membrane of the pharynx. Erythema of alcohol should go to regular hospitals in time, choose appropriate treatment such as medication under the guidance of professional doctors, and drink more water to promote excretion.