Alcohol intolerance and allergies: Symptoms & causes

September 2024  |  ✓  Medically Reviewed by: Gary Falcetano, PA-C, AE-C & Magnus Borres, Director of Medical Affairs

Picture this: it's Friday night, the week's stress is behind you and it's time to unwind with a frosty cold beer or a glass of wine. You take those first few sips and sink into your favorite chair. But, instead of relaxation, you’re greeted with a wave of nausea and red blotches begin to appear on your face, neck and chest. Is it just a weird coincidence, or could it be something else? They could be symptoms of unexpected alcohol intolerance.  

Let’s shed some light on this often-confusing topic and figure out why a glass of bubbly doesn’t always lead to good times. It’s also important to learn the differences between alcohol intolerance and alcohol allergy to identify and better manage symptoms. Cheers to knowledge!

What is alcohol intolerance?

Alcohol intolerance is a physical reaction that can happen immediately or shortly after drinking alcohol. It’s not an allergy in the typical sense, but it can feel like one. It occurs when the body can’t properly break down the toxins in alcohol leading to not-so-festive symptoms.1

Difference between alcohol intolerance and alcohol allergies

It is easy to confuse alcohol intolerance with an alcohol allergy. While both can ruin a good party, they have different causes and symptoms. The main difference? Alcohol intolerance is a genetic, metabolic disorder of the digestive system, while an alcohol allergy is an immune system response to an ingredient in alcohol.2

It's important to note that both can be serious and if you suspect you have either, it's best to consult with a healthcare professional. 

Alcohol intolerance vs. alcohol allergy

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Did you know?

Alcohol itself isn’t usually the allergen that triggers allergic reactions. Certain ingredients in alcoholic beverages can be the cause.2

  • Grains: Alcoholic beverages like beer and whiskey often contain wheat, barley, or rye grains. Some people may have allergies to these grains, which can trigger reactions when they consume these drinks.
  • Sulfites: These substances are often used as preservatives in wine and beer. Some people may be sensitive or allergic to sulfites, experiencing symptoms like flushing, abdominal pain and diarrhea.5
  • Histamines: These are chemicals that can be found in alcoholic beverages, particularly red wine and some beers. They're produced by yeast and bacteria during the fermentation process.
  • Other ingredients: Some people might be allergic to other ingredients used in certain alcoholic beverages, such as fruit or nut-based liqueurs or certain additives.

Learn more about specific allergens.

What causes alcohol intolerance?

Alcohol intolerance is primarily caused by an enzyme, aldehyde dehydrogenase (ALDH2), deficiency. If you're deficient in ALDH2, you may experience uncomfortable symptoms after consuming alcohol.4

Here's how it works: when you drink alcohol, it's broken down in your body into a chemical called acetaldehyde. Normally, acetaldehyde is further broken down into a harmless substance called acetate by ALDH2.6 For people with alcohol intolerance, this process is impaired because the ALDH2 is less active, causing acetaldehyde to build up in the blood and tissues, causing symptoms.2

Alcohol intolerance symptoms

Unwelcome at any celebration, symptoms of alcohol intolerance typically appear shortly after alcohol consumption and can vary in severity. They may include:1

  • Flushing: A red, warm face and neck
  • Nasal congestion: Stuffy/runny nose and sinus pressure
  • Nausea and vomiting: Gastrointestinal discomfort
  • Rapid heartbeat: Increased heart rate and palpitations
  • Low blood pressure: Feeling light-headed or faint
  • Diarrhea: Speaks for itself!

Diagnosis of alcohol intolerance

Alcohol intolerance is typically diagnosed through a combination of self-observed symptom tracking, a detailed medical history and a physical exam. A healthcare provider will ask about your symptoms, their frequency and duration, and what types of alcohol seem to trigger them.

If an allergy to a certain ingredient in alcoholic drinks is suspected, an elimination diet may be recommended. This involves avoiding the suspected allergen to see if symptoms improve. Allergy tests such as skin prick or blood tests may also be conducted to identify specific allergens.

Consulting with a healthcare provider is essential for an accurate diagnosis.

This allergy symptom questionnaire can help organize your symptom notes to guide a productive conversation!

Alcohol intolerance treatment options

Treatment for alcohol intolerance can include some lifestyle changes that can help manage the symptoms of alcohol intolerance, but they don’t solve the root cause of the intolerance. The absolute best treatment option is to limit or avoid alcohol completely.1

Lifestyle changes

Living with alcohol intolerance can be a real party crasher, but some lifestyle adjustments can help. Here are a few:

  • Choose wisely: If you still wish to consume alcohol, choose drinks that are low in sulfites and other preservatives, as these could be triggering your symptoms.1
  • Stay hydrated: Drinking plenty of water before, during, and after consuming alcohol can help to dilute it in your system and reduce symptoms.7
  • Eat beforehand: Consuming alcohol on an empty stomach can worsen symptoms of alcohol intolerance. Eating a meal before drinking can help to slow the absorption of alcohol.7
  • Monitor reactions: Pay attention to which types of alcohol seem to trigger your symptoms. You might find that you tolerate certain types of alcohol better than others.
  • Consult a healthcare professional: If your symptoms are severe or if you're concerned about your reactions to alcohol, it's a good idea to consult a healthcare professional. They can provide advice tailored to your circumstances.

Not sure if you have alcohol intolerance or allergies? Learn how to get an allergy test.

If an allergy to an ingredient in alcohol is suspected, an allergy test may be recommended. A blood allergy test, also called a specific IgE test, is a powerful diagnostic tool that can pinpoint what allergen may be causing your symptoms. This test measures the concentration of IgE antibodies in the blood that indicates a sensitization to a specific allergen. It could be the grains in beer or those lovely fruit notes in wine.

While a blood allergy test can help identify an allergy to certain components in alcoholic beverages, it won't confirm alcohol intolerance. It’s important to consult with a healthcare provider, who can provide appropriate testing and treatment options based on a detailed medical history and observation of symptoms.

  1. Mayo Foundation for Medical Education and Research. (2023b, April 6). Alcohol intolerance. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/alcohol-intolerance/symptoms-causes/syc-20369211
  2. Cleveland Clinic Medical. (2020, August 24). Alcohol intolerance: Symptoms, tests & alcohol allergy. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/17659-alcohol-intolerance
  3. Vally H, Thompson PJ. Allergic and asthmatic reactions to alcoholic drinks. Addict Biol. 2003 Mar;8(1):3-11. doi: 10.1080/1355621031000069828. PMID: 12745410.
  4. Brooks PJ, Enoch MA, Goldman D, Li TK, Yokoyama A. The alcohol flushing response: an unrecognized risk factor for esophageal cancer from alcohol consumption. PLoS Med. 2009 Mar 24;6(3):e50. doi: 10.1371/journal.pmed.100050. PMID: 19320537; PMCID: PMC2659709.
  5. Vally H, Misso NL. Adverse reactions to the sulphite additives. Gastroenterol Hepatol Bed Bench. 2012 Winter;5(1):16-23. PMID: 24834193; PMCID: PMC4017440.
  6. Zakhari, S. Overview: How is alcohol metabolized by the body? Alcohol Research & Health 29(4):245–254, 2006. PMID: 17718403
  7. Hindle, RD LD, N., & Orazio, PhD MPH, E. (2022a, May 11). Food and alcohol: What you need to know. Johns Hopkins University Student WellBeing. https://wellbeing.jhu.edu/blog/2022/05/11/food-and-alcohol-what-you-need-to-know/