A true wine allergy is relatively rare, but it can cause severe symptoms. Some patients even suffer an allergic shock (anaphylaxis). In 2005, Dr. Susanne Schäd and her colleagues at the University Dermatology Clinic in Würzburg, Germany, reported on a 27-year-old woman who developed itchy palms, swelling of the eyes, lips, and tongue, difficulty breathing, difficulty swallowing, and circulatory problems within an hour of drinking red wine, sparkling wine, grapes, or raisins. The cause was an allergic reaction to lipid transfer proteins (LTP) in grapes.
LTP as a trigger of the allergic reaction.
Allergenic LTP are found, for example, in some fruits and vegetables such as peaches, cherries, corn, asparagus, and lettuce. Lipid transfer proteins are common triggers of allergies in the Mediterranean region.
For example, the case of a young woman who fainted several times after drinking champagne is reported from Spain. However, she only suffered an allergic shock when she ate grapes in addition to sparkling wine. Little is known so far whether LTP can also be a trigger of anaphylaxis in our country.
What is anaphylactic shock?
Anaphylactic shocks are life-threatening. The most common triggers are insect venoms, foods such as peanuts or celery, and drugs. It is vital to identify the trigger through allergy testing. People at risk must carry emergency medications at all times.
“Allergy to insect venom can be treated very well with specific immunotherapy. Almost all patients are protected from allergic shocks caused by insect venom after this causative therapy,” says Munich-based Professor Dr. Bernhard Przybilla of the German Society for Allergology and Clinical Immunology (DGAKI).
Not at all rare: Allergy symptoms after alcohol consumption
However, quite a few people suffer from allergy symptoms in the respiratory tract or skin after drinking various alcoholic beverages. A Danish study published in 2008 concluded that 13 percent of adults had already experienced such symptoms after drinking alcohol during their lifetime. The symptoms occurred most frequently after red wine, more often in women than in men. The pathomechanisms of these reactions are still unclear and presumably diverse. Very rare are anaphylactic reactions to ethanol itself.
Epidemiological studies showed that people who drink alcohol more frequently suffer more from allergic rhinitis and asthma. In an earlier study of 3,317 patients, Danish scientists found that those who drank alcoholic beverages several times a week were more likely to be sensitized to airborne allergens (aeroallergens).
Insect venom allergy from wine?
In the summer of 2007, Spanish physicians reported five patients who experienced allergy symptoms after drinking grape juice or young wine. One patient even suffered anaphylactic shock. A skin test to detect allergy was positive with the suspected wine, but not with other, older wine samples. In contrast, tests with insect venom were positive, although none of the patients reported a previous bee or wasp sting.
The puzzle’s solution: Insect venom is detectable in grape juice and young wine. When grapes are pressed, insects probably also get into the product. The Spanish scientists believe that even these small amounts of toxin are sufficient to cause sensitization and allergy symptoms in sensitive people via the oral route. It is possible that the toxins decompose as the wines age, making older wines safe.
“An interesting observation – however, this pathway of developing allergy and triggering anaphylaxis remains hypothetical for now,” comments Professor Przybilla. “Thus, the actual triggering of symptoms by insect venom could have been secured by an oral provocation test with insect venom. However, such a test was obviously not performed.”
