Itching all over the body after drinking alcohol should be considered whether the phenomenon of alcohol allergy has occurred, mainly due to the lack of acetaldehyde dehydrogenase in the body. The lack of acetaldehyde dehydrogenase causes the body to be unable to rapidly break down and metabolize alcohol, which increases the burden on the liver, resulting in itching, even red skin and blushing after drinking. There are individual differences in the amount of acetaldehyde dehydrogenase produced. Some people can produce more acetaldehyde dehydrogenase and will not experience redness and itchy skin after drinking, while others are born with less secretion of acetaldehyde dehydrogenase and will experience redness and itchy skin after drinking. At the same time, attention should be paid to exclude whether other drugs or food are taken before or after drinking alcohol, which leads to toxic reactions, such as disulfiram-like reactions that occur clinically most commonly when alcohol is consumed after using cephalosporins.