KEY TAKEAWAYS
An alcohol allergy is an immune system reaction to alcohol that may be life-threatening in rare cases [1].
Allergic reaction to alcohol itself does exist, but is rare.
Instead, it's more common to experience an allergic reaction to wheat, rye, yeast, or other ingredients in alcoholic drinks.
Allergy To Alcohol Itself
Allergic reactions to alcohol itself, differ from flushing, irritation, or intolerance to alcohol [2].
Those with alcohol allergy experience severe rashes, stomach cramps, breathing problems, or collapse, when they consume as little as 1 ml of pure alcohol [2].
This is equal to a mouthful of beer, or 10ml of wine.
It is unusual to have a true allergy to alcohol, but common to experience allergy-like symptoms after consuming alcohol due to intolerance or being allergic to other ingredients in the beverage [3].
Chemicals like congeners, found in red wine, also cause allergic reaction.
Alcohol exacerbates conditions like asthma, rhinitis, and urticaria, causing headaches, wheeziness, and skin flushes, and presents as alcohol intolerance [3].
A food allergy or sensitivity to a specific food type may present as an alcohol allergy.
This is because alcohol increases permeability of the gut wall - thus allowing greater absorption of food to which a sensitivity exists.
Causes of Alcohol Allergies
With a true alcohol allergy, the immune system over-reacts when it comes in contact with alcohol.
The body responds by producing antibodies [4].
While true alcohol allergy is rare, the reactions are usually severe.
Allergens In Alcoholic Drinks
It is possible to be allergic to the components of alcoholic drinks, and not alcohol itself.
Allergens in alcoholic beverages include [5]:
Aside from drinking alcoholic beverages, foods like marinades, overripe fruit, mouthwash, tomato puree, and cough syrup cause an alcohol allergic reaction.
At-Risk Groups For Alcohol Allergy
Alcohol allergic symptoms are pronounced in those of Asian descent (Asian alcohol allergy), individuals allergic to grains, and those with asthma, hay fever, or Hodgkin's Lymphoma [5].
Signs & Symptoms Of Alcohol Allergy
With an authentic alcohol allergy, the smallest amounts of alcohol causes symptoms and anaphylaxis in severe cases [6].
Anaphylaxis includes rash, shock, and low pulse, tachycardia, fainting, and is life-threatening [7].
If an individual drinks alcohol and experiences any of these reactions, an alcohol allergy is suspected.
Researchers are unable to explain why certain people have allergic reactions to alcohol, when the body naturally produces very small amounts already.
In rare cases, alcohol allergic reactions are life-threatening, or fatal.
Allergic reaction to alcohol does not occur exclusively the first time alcohol is consumed [1].
Alcohol allergies can develop later in life, and they may manifest suddenly.
For example, suddenly feeling pain after drinking alcohol is a possible symptom of Hodgkin's lymphoma [8].
Alcohol Allergy vs Alcohol Intolerance
Being allergic to alcohol is not the same as alcohol intolerance [9].
Alcohol intolerance is a metabolic, genetic disorder of the digestive system that prevents the body from processing alcohol as it is supposed to [10].
Whereas, alcohol allergy is an immune system response where the body reacts to alcohol itself or an ingredient in the alcoholic beverage, including chemicals, preservatives, or grain.
Alcohol intolerance occurs when the body lacks the proper enzymes to metabolise alcohol and its substrates [11].
The genetic trait of alcohol intolerance is often found in Asians [12].
When an individual consumes alcohol, the ethanol is processed by alcohol dehydrogenase (ADH), an enzyme in the body.
The liver converts ethanol to acetaldehyde, and since this causes cell damage, another aldehyde dehydrogenase 2 (ALDH2) converts it to non-toxic acetic acid [13].
When an individual has alcohol intolerance, ALDH2 is less active, causing acetaldehyde to build up and cause symptoms and reactions [10].
Signs Of Alcohol Intolerance Include [10]:
Symptoms of alcohol intolerance differ.
The symptoms of alcohol intolerance and alcohol allergy differ slightly, but both cause nausea.
Flushed skin is the main symptom that separates alcohol intolerance from an allergic reaction.
Alcohol intolerance symptoms frequently confused with alcohol allergy include [1]:
Other Explanations Of Alcohol Reaction Symptoms
Symptoms that happen after drinking alcohol are not always caused by an allergic reaction or intolerance to alcohol.
Individuals react to substances in alcohol, like sulphites or histamine [2].
Histamine Intolerance
Histamine is present in red wines and other alcoholic drinks.
Those intolerant to histamine experience headaches, flushing, asthma, and nasal and gut symptoms [3].
The amount of histamine in alcohol differs.
Histamine is metabolised by the enzyme diamine oxidase [14].
Individuals unable to produce enough enzymes can have a severe allergic reaction whenever alcohol or any food with histamines is consumed.
Sulphite Intolerance
Sulphites are preservatives added to alcoholic beverages like wine and beer in certain countries, but can generate side effects like hives, stomach pain, swelling, diarrhoea, etc [15].
Sulphites are found in home-brewed wines and beers because they are used to clean brewing equipment.
Sulphite intolerance restricts breathing and causes skin reactions, abdominal pain, and diarrhoea [16].
One in ten asthmatics is sensitive to sulphites, making them wheeze after consuming alcoholic beverages [3].
Rashes and anaphylactic reactions are rare with sulphite intolerance.
Hodgkin's Lymphoma
Hodgkin's Lymphoma is a blood cancer affecting the lymphatic system [17].
Hodgkin Lymphoma causes swelling in lymph nodes in the neck, groin, and armpits.
Those with swollen lymph nodes are unable to feel pain, although they experience pain after drinking an alcoholic beverage [18].
The exact cause of pain in lymphoma after drinking alcohol is unknown, but it is suspected that blood vessels in the lymph nodes dilate after exposure to ethanol [19].
Risks of Alcohol Sensitivity
The main risk of an alcohol allergy is anaphylaxis, although this is rare.
Anaphylaxis is a medical emergency and is treated by medical personnel.
Aside from this, other unpleasant symptoms are treated with a prescribed epinephrine autoinjector, often called an EpiPen [20].
Diagnosing Alcohol Allergies
If a patient suspects an alcohol allergy, eliminating alcohol intake, and consultation with a healthcare professional is important.
An allergist asks questions about symptoms and medical history before conducting allergy testing.
The skin prick test is the common form, but an oral challenge test is possible, although it requires the patient to drink alcohol.
Allergy testing is done in a medical setting due to the risk of allergic reactions.
Treatment For Individuals Who Cannot Drink Alcohol
The best way to treat alcohol allergy is to simply avoid alcohol consumption entirely [1].
Mild symptoms may be treated with over-the-counter medication or an EpiPen can be administered for more severe acute episodes such as anaphylactic shock.
