Alcoholic beverages may cause allergic reactions

An allergy to alcohol itself – that is, ethanol – is extremely rare.

The most common ingredients of alcoholic beverages that may cause hypersensitivity are sulphur dioxide, histamine and colourants. The most typical symptom is sudden hives, which can easily escalate to an anaphylactic reaction: sudden hypersensitivity. The amount that typically causes such a reaction is 8-10 grammes of alcohol. This type of allergy seems to be incurable and its aetiology has not been fully determined.

Alcohol can also cause a sudden hypersensitivity reaction via non-allergic mechanisms, such as during a flu, when a hungover person goes jogging or when someone exerts themselves enough to break out in a sweat. Alcohol may exacerbate asthma and allergy symptoms non-specifically, and abundant consumption also increases the risk of sensitivity and elevates allergy-related immunoglobulin E (IgE) levels in blood serum.

Sudden flush from alcohol

Even a small amount of alcohol can cause flushing of the face and upper chest, which lasts for several dozen minutes, but this is not an allergic reaction. Contributing factors include menopause, acne rosacea, sensitivity to flushing (hereditary) and stress in social situations.

Sudden flushing may sometimes also be connected to medication, such as Antabus treatment for alcoholism. Oral metronidazole medication may also cause an Antabus-like reaction in some people. About 6% of patients using tacrolimus ointment (Protopic®) have also had flush reactions. A sauna intensifies this reaction.

Wine headache

Many persons who are susceptible to headaches, and allergic persons in particular, often get a migraine-like headache from even just one glass of red wine. This is one symptom of the so-called red wine headache syndrome.

It also involves a bad hangover whose severity is out of all proportion to the amount of wine consumed. Not much is known about this syndrome: not its prevalence, cause or mechanism. Many researchers believe that a wine headache is often psychological, caused by a single prior experience of a severe wine hangover.

More information: Allergy, Skin and Asthma Federation