A red rash on the body after drinking alcohol can be caused by an alcohol allergy or an irritation reaction to alcohol. 1. Alcohol allergy: Red rash after drinking alcohol is mostly seen in the case of alcohol allergy. In addition to the red rash after drinking, it can also be accompanied by other symptoms such as itching and swelling of the whole body. When there is an allergy to alcohol, it is necessary to stop drinking immediately and carry out anti-allergy treatment, usually oral cetirizine tablets or loratadine tablets and other medications for treatment. 2. Alcohol stimulation reaction: If you only have a red rash on your body after drinking alcohol without other obvious abnormal symptoms, you may consider that it is alcohol stimulation reaction, which is caused by the accelerated blood flow in the skin after drinking alcohol, and it can be eliminated by yourself in a few hours after stopping drinking alcohol, without any special treatment. People who are allergic to alcohol are advised not to drink alcohol to avoid severe allergic reactions that could be life-threatening. People who have an irritant reaction to alcohol are also advised not to drink alcohol to avoid damage to the body. If a rash appears after drinking alcohol, it is recommended to stop drinking and go to the hospital to avoid delaying the condition.