Allergic reactions to alcohol

Hi,
My husband is 28 years old. He has had an allergy to Whiskey and other dark liquors for a long time...since he first started drinking. He would get a red blotchy rash on his chest, neck, sometimes arms and feel "very drunk" after just a drink or two. We decided it was just one of the ingredients in that "type" of liquor. About 4 months ago he had the same reaction to Vodka, Then Run, and now he is getting it with beer! The only change in the reaction is that every time he drinks it takes less alcohol to give him the reaction and the reaction is getting stronger. He said once that it made him feel like he had a harder time breathing and would not explain and he gets very dizzy. Is he allergic to alcohol? The ingredients? Or anaphylactic? Or could it be a symptom of something entirely different?? Diabetes runs in his family....