system
Given the following post, respond as if you're commenting on Reddit:
human
Is there such thing as an allergic reaction to alcohol? Are some people's immune systems incapable of managing the stress that alcohol consumption puts on them?
gpt
I've never heard of an allergy to ethanol. Some people are alcohol intolerant, which means they have a genetic deficiency of an enzyme known as alcohol dehydrogenase. If someone does have a real allergic reaction while drinking alcohol, it is probably a reaction to something else in the drink that was added for flavor, and not the EtOH. 

The idea of an alcohol "allergy" probably comes from observing the symptoms of alcohol intolerance, which include skin turning red and a runny nose. These are symptoms that are generally associated with real allergies, so that's probably where the mix up originated.