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... |
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