The "allergy" concept was coined by a doctor in the 1930's who was working with alcoholics. It has never been updated in the text of AA since, in spite of medical and scientific advances in knowledge in the 80 plus years since. It's a concept that seems to be exclusive to AA and their 12 step philosophy of recovery. The THIQ theory is treated as scientific evidence when, in reality, it's not, or at least not yet.