Alcohol allergy

You must have heard people saying that after drinking just one alcoholic beverage they get a rash all over the body. It is absolutely normal for these people to wonder whether or not they are allergic to alcohol. However, many of them do not believe it is possible they are allergic. This is definitely possible, although allergic reactions to alcoholic beverages are uncommon. By contrast, non-allergic adverse reactions to alcohol such as flushing, irritant reactions, toxic reactions and psychological effects are more common then allergic reactions.
 

What is alcohol allergy?

The first thing you need to know is that if you think you may suffer from an allergy or another disease that requires attention, you should discuss it with your family doctor. Next, you should know that alcohol can cause a variety of immediate adverse effects on the body. Studies show that some people are more sensitive to these effects than others are. However, this does not mean that they have an alcohol allergy. The truth is that allergic reaction involves the immune system, so alcohol can cause headaches, rapid heartbeat and nausea. Some people are especially sensitive to the stomach-irritating effects of alcohol. These people may develop heartburn, abdominal pain and even vomiting. Alcohol can also increase blood flow to parts of the body, such as the skin and the lining of the nose which may result in warm, red, sometimes itchy skin, as well as nasal congestion. Rarely, a person may develop sensitivity to the preservatives used in some wines and beers but this situation is really rare. Many people of Asian descent experience an unusual flushing reaction after drinking alcohol. That happens even if very small amounts of alcohol are consumed. This is caused by a genetic disorder in which the body is unable to break down alcohol completely, and research suggests that people who experience alcohol flush reaction may be at increased risk of alcohol-related conditions, such as cancer of the esophagus and liver disease.
The only solution to all of these problems is to avoid alcohol, which is recommended for everyone, whether there is an alcohol allergy or not.

Identifying your allergy

It is extremely important for you to identify your allergy if there is any. Maybe you know that there is something in wine and beer that produces an adverse reaction, but you are not exactly sure what. So what should you do? Some doctors suggest that you learn all the ingredients that are present in the beverage you are reacting to. Then you might undergo a skin-prick test. If anything shows up then you are allergic, but if nothing shows up then you are likely to have an intolerance. If you are intolerant, then you can undergo a food challenge, by using specific ingredients via a capsule to see what it is that you are reacting to. This is simply to eliminate the offending ingredient from your diet and prevent further allergic reactions.

More about alcohol

Alcohol, or ethanol, is a natural product, a normal byproduct of human and animal cell chemistry (metabolism). Cell processes result in normal physiological levels of 0.01 to 0.03 mg of alcohol/100 ml of blood and by contrast, a blood alcohol limit for driving of 0.05 per cent is equivalent to 50 mg of alcohol/100 ml of blood. It is also important to know that alcohol is broken down in the liver, by liver enzymes within minutes. Conversion of ethanol to acetaldehyde requires the enzyme alcohol dehydrogenase so acetaldehyde is then transformed to acetic acid or vinegar by the enzyme aldehyde dehydrogenase. If individuals cannot break down alcohol easily, problems may occur when alcohol is consumed.

Flushing is not an allergic reaction

Some patients will experience intense facial flushing after having even small amounts of alcohol and these symptoms are most common in those with an oriental or Asian background. Other side-effects of fluttering of the heart (palpitations or tachycardia), sensation of heat, headache, tummy discomfort or a drop in blood pressure (hypotension), are related to high blood acetaldehyde levels. Individuals with these problems appear to be partially deficient in aldehyde dehydrogenase. This results in high levels of accumulated acetaldehyde.
Other conditions may also trigger flushing, since not all flushing is due to alcohol. Flushing can occur in skin conditions such as rosacea, the menopause, low blood sugar levels, and sometimes as a response to some antibiotics or medicines used to treat diabetes or high blood fat levels.  As you’ve already heard, the liver breaks down the alcohol or ethanol we drink and converts it to a chemical called acetaldehyde. Acetaldehyde is then transformed to acetic acid or vinegar, but problems occur if alcohol cannot be broken down. As well as ethanol, alcoholic beverages contain a complex mixture of grape, yeast, hop, barley or wheat-derived substances, natural food chemicals, wood and fruit-derived substances, added enzymes and preservatives. Severe allergic reactions have been described in people with allergies to proteins within grapes, yeast, hops, barley and wheat, which means these patients are not sensitive to alcohol itself.

Conditions related to alcohol reaction

Asthma can be triggered by sulfites; up to a third of asthma patients complain that wine will worsen their asthma, less often with beer or spirits. Beer, wine and champagne contain sulfites, used as a preservative since Roman times. Some people, particularly those with unstable or poorly controlled asthma, may wheeze when they drink and develop something like an allergic reaction. In general, there is more preservative in white wine than red wine, and more in cask wine than bottled wine, while the amount of metabisulfite also varies from brand to brand. There are some low-sulfite wines available, although those with extreme sensitivity may not be able to tolerate them. The reason is that some grape growers will dust sulfur powder over grapes in the weeks leading up to harvest. Other sources of sulfites include vinegar, pickled onions, dried fruit, and some restaurant salads or fruit salads; sometimes grapes are transported with bags of sulfite to keep them fresh.
Even when people complain that wine triggers asthma, sulfite may not be the only explanation for this problem. Asthma can also be due to enzyme deficiency where patients with aldehyde dehydrogenase deficiency accumulate high levels of acetaldehyde after consuming alcohol. Acetaldehyde has been blamed for asthmatic reactions to alcohol in up to half of Japanese asthma patients so sometimes histamine within alcoholic beverages was blamed for allergic reactions. Histamine and other substances may also cause problems because histamine can trigger sneezing, runny nose and sometimes wheeze, stomach upset and headache. There is more histamine in red than white wines but the amounts will vary from wine to wine. Some small studies have shown that antihistamines can help reduce the severity of symptoms. If the amount of wine challenge was equivalent to only one glass, it probably will not prevent hangovers. Some others substances within wine may also cause problems to some unlucky individuals, but these are not well defined.

Serious allergic reactions to beer or wine

Anaphylaxis has been described in patients with severe allergic reactions to proteins within grapes, yeast, hops, barley and wheat, but these patients are not sensitive to alcohol itself. Anaphylaxis to alcohol is as rare as allergic reactions to alcohol. Although these allergic reactions are rare, they are described in a few dozen published case reports.
As little as 1 ml of pure alcohol, equivalent to 10ml of wine or a mouthful of beer, is enough to provoke a reaction. This could be severe rashes, difficulty breathing, stomach cramps or collapse, a condition known as anaphylaxis. Given that the body itself constantly produces small amounts of alcohol, the reason that such reactions occur is poorly understood and allergy tests using alcohol are usually negative. However, these tests are sometimes positive to breakdown products of ethanol such as acetaldehyde or acetic acid. Provocation tests with alcohol are usually positive, but only when acetaldehyde or acetic acid is used, and finally, alcohol can sometimes act as a co-factor. This means alcohol is increasing the likelihood of anaphylaxis from other causes.

Management of alcohol allergy

Accidental exposure may lead to unexpected reactions, so patients with alcohol allergy should be managed in the same way as others with serious allergic reactions. The patient must identify and avoid the cause, wear a Medic Alert bracelet, and carry adrenaline or epinephrine as part of an emergency action plan. This is especially important if they are at risk of dangerous allergic reactions in the future. Moreover, alcohol can worsen symptoms in patients with hives called urticaria. Occasionally, alcohol can also trigger hives directly, where as with more serious allergic reactions, the mechanism is unclear. Less common reactions include localized contact hives and contact dermatitis, but you must remember that not all adverse reactions to alcohol are due to allergy. Other effects of alcohol toxicity are well known, including its effect on the liver, stomach, brain and mental functioning, especially in large amounts. Even though alcohol has a relaxant effect on the brain, some individuals will experience paradoxical agitation and anxiety, which is due to the drug-like activity of alcohol.