Allergic reactions to beer range from hives (urticaria) and swelling (angioedema) to severe anaphylaxis. Typically the reactions are after ingestion as opposed to just skin contact.
How is beer made?
Beer is formed by the breakdown of complex carbohydrates to monosaccharides (simple sugars) that are then fermented. Malted cereals such as wheat or barley are the most commonly used starches. Other “starting agents” for beer include rice, corn, rye and potato. When hops (Humulus lupulus) are added, this not only adds the bitter taste, but also functions as a natural preservative. The fermentation process occurs when the brewer’s yeast (Saccharomyces cerevisiae) is added.
Reactions to beer can be due to:
Accumulation of acetaldehyde: this occurs in up to 40% of persons of Asian descent who are unable to metabolize alcohol due to a mutation in the gene ALDH2 that codes for the protein alcohol dehydrogenase. Symptoms are flushing, nausea and increased heart rate.
Allergy via IgE antibody: Since alcohol is a simple compound, it cannot generate IgE antibodies, but the breakdown products of alcohol could. This could involve the mechanism of having a hapten.
The allergic antibody (IgE) can be directed at one of the grains such as wheat or barley. The reaction can be directed to the modified grain protein (malt extract) after the fermentation process. The 10-kiloDalton protein called Lipid Transfer Protein (LTP) is nonspecific and similar to that found in Rosaceae fruits and some vegetables. LTP can withstand the germination and fermentation process making it a relevant allergen. Isolated respiratory reactions after drinking beer can be due to prior sensitization to yeast, molds or grains. To date, prospective studies using immunoblotting have failed to show yeast antigen in bakery and brewery products.
Can beer cause anaphylaxis?
Yes, anaphylactic symptoms after ingesting beer can include hives, swelling, rhinitis/conjunctivitis (nasal and eye allergies), chest tightness, dyspnea (shortness of breath) and even loss of consciousness. There has been a report of exercise-related anaphylaxis after drinking wheat beer (same protein [gamma gliadin] as that found in those with eating wheat products).
Can hops be the trigger?
Nope! At this time, there have been no reported cases of allergic reactions to beer triggered by hops. However, in some hop-picking farmers, they can develop occupational allergies, hives or asthma; but not from drinking beer.
After living in Milwaukee, Wisconsin (beer capital of the world http://www.beerhistory.com/ ), for many years, I appreciate the effect on quality of life that allergic reactions to beer can cause. In my quest for information on beer, I have personally toured Miller and Sprecher breweries in the U.S.
At Family Allergy Asthma & Sinus Care, we investigate beer-induced reactions, so if you believe you have experienced a reaction, contact us. We are here to help! Cheers...