A glass of wine, sometimes just two sips, and your face becomes red, hot, sometimes spotted with plaques. Many see it as a simple embarrassing reaction, which we can have fun with. However, behind this very common phenomenon lie very specific biological mechanisms, and sometimes real health risks. As Dr. Gérald Kierzek, emergency physician, reminds us, these red spots are never trivial.
When wine “brings fire to the face”
The phenomenon is well known. According to Dr. Gérald Kierzek,
Red patches most often appear due to facial vasodilation caused by alcohol or certain components of wine, such as histamine or sulphites. This triggers a hot flash and transient redness..
Concretely, the blood vessels located under the skin of the face suddenly dilate, which reveals the red of the blood and gives this impression of heat rising to the face, sometimes up to the neck and décolleté.
But this reaction, as visible as it may be, can have several very different origins.
The ALDH2 gene: when alcohol becomes toxic
In part of the population, especially of Asian origin, redness is not a simple sensitivity. It is genetic. About 8% of people have a variant of the ALDH2 gene, called ALDH2*2. This gene controls the production of an enzyme responsible for eliminating alcohol after consumption.
When this enzyme malfunctions, alcohol is transformed into acetaldehyde, a toxic substance, which accumulates in the body. It is this accumulation that causes flushing, palpitations, headaches and sometimes discomfort. Dr Gérald Kierzek then talks about
“alcoholic flush”a biological warning signal.
Work carried out at Stanford University has shown that in carriers of the ALDH2*2 gene, even a small amount of alcohol impairs blood vessel function. In other words, “a simple standard drink is enough to create vascular inflammation”.
In these people, any alcohol consumption becomes potentially dangerous, especially if there are risk factors such as high blood pressure, cholesterol or a family history of heart disease.
Histamine and sulphites: common culprits
For many other people, the rash does not come from the alcohol itself but from the substances it contains. Red wine is naturally rich in histamine, produced during fermentation. This molecule is also involved in allergic reactions. When it accumulates in the body, it can cause redness, headaches, palpitations and sometimes respiratory problems, especially in people with asthma.
White wine and champagnes, for their part, contain more sulphites, used as preservatives. Here again, Dr Kierzek recalls that these substances “release endogenous histamine in people with intolerance “, which explains the appearance of red patches, feelings of heat and sometimes chest tightness. This is not an allergy in the strict sense, but a chemical intolerance, dependent on the dose.
Wine allergy: rare, but real
In rare cases, redness is a sign of a true allergy. Wine can contain many potential allergens: grape proteins, yeasts, molds, additives such as lysozyme, even traces of insects such as bees or wasps. Dr. Kierzek recalls that ” the true IgE allergy to wine exists, but it is rare”.
A grape allergy can also be involved, sometimes associated with cross allergies with apple, peach or certain pollens. Unlike intolerances, allergies trigger more obvious symptoms: itching, hives, facial swelling, breathing difficulties. In this case, an assessment by an allergist is essential.
Visible plaques: should you continue drinking?
It all depends on the origin of the redness. If they are mild, limited to the face and without other symptoms, Dr Gérald Kierzek simply advises moderating your consumption and trying wines low in sulphites. On the other hand, it clearly warns of the genetic flush linked to ALDH2: “In these people, the redness is not benign. It reflects a toxic accumulation which increases the cardiovascular risk. Alcohol should be completely avoided.”
As Dr. Gérald Kierzek summarizes, the body never blushes for nothing: it signals that it is in difficulty with alcohol. Listening to this message does not mean giving up pleasure, it sometimes means avoiding a very real danger.