Aphthae – What are the causes of the small bubbles in the mouth?

General information

A sudden, unpleasant feeling in the mouth, especially when you eat something or even when you talk. If you look more closely in the mirror, you will notice a small white bubble in the oral cavity, which is located on the mucous membrane. If you touch it with your finger, this unpleasant pain flickers through again. This is most likely an aphtae, which usually does not appear for the first time. But what are the causes of aphthae and what can you do about it?

Causes of aphthae

The exact cause of aphthae is not yet known. However, it is assumed that there are various factors that favour its development, as well as a genetic predisposition. So far it is known that gluten is a possible cause of aphthae in people who suffer from gluten intolerance.

Furthermore, a lack of vitamin B12, iron or folic acid promotes the development. A changed hormone balance is also associated with the development. Especially during pregnancy, the menopause and in connection with the menstrual cycle, an increased incidence of aphthae is observed.

Thus, women suffer from aphthae more frequently than men. In addition, after various studies it was found that certain foods can also influence the development. These include walnuts and hazelnuts (also as a component of chocolate), citrus fruits, tomatoes, very spicy dishes or alcoholic drinks.

Smokers have been shown to have an increased aphthae formation, which may be related to the deposits that form on the mucous membrane of the mouth during smoking. This results in increased keratinization of the epithelium. Another important component is a strong immune system, because a weakened one has an increased risk of developing aphthae.

With a weakened immune system, the body does not have as much energy available to fend off pathogens, so they have an easier time causing inflammation. In this context, HIV should also be mentioned. HIV patients show an increased susceptibility to aphthae, which can be attributed to the fact that HIV patients have a weakened immune system due to the virus.

But also other systemic diseases, such as chronic intestinal diseases or Behcet’s disease can trigger the aphthae. Behcet’s disease is a multisystemic disease that affects the blood vessels. Herpes and influenza viruses are also associated with the formation of aphthae.

Conversely, frequently occurring aphthae can also be a sign of a disease. A stressful everyday life and mental suffering can affect the organism and, among other things, be involved in the formation of aphthae. Aphthae are often said to be contagious, but this is not correct.

The cause lies with the person affected and cannot be passed on. Only possible causes, such as viral infections, can be transmitted. The blister in the mouth does not always have to be an aphthae.

HIV is not the direct cause of aphthae, but it can be the reason why they occur more frequently. An HIV positive patient has a weakened immune system after several years, which means that small wounds and resulting inflammation in the mouth are not easily combated by the immune system. Aphthae are often seen as a sign of a recent HIV infection.

However, since the weakness of the immune system only manifests itself after several years, not every aphthae is concerned about an acute infection. In affected patients, recurrent large aphthae occur simultaneously in several places. The fact that the ingredients of some toothpastes could be a possible cause of aphthae is still controversially discussed.

The substance in question is sodium lauryl sulphate, a detergent, i.e. a washing-active substance which is also contained in detergents. Its function is to dissolve proteins and thus bind and remove “dirt”. It is also said to have an antibacterial and also antiviral effect.

However, the ingredient, which is not contained in all toothpastes, is criticized because it is said to have an allergenic and skin-irritating effect. These properties naturally favour the development of an aphthae. As explained in the section Causes, a weakened immune system can lead to an increased incidence of aphthae.

This immunodeficiency can be caused by a lack of vitamin supply, among other things. In the case of the oral mucosa, the main cause is folic acid or vitamin B12 deficiency. In addition, an insufficient iron balance favours the formation of aphthae, which also explains why women are more frequently affected than men.

If aphthae occur more frequently, a blood test should be performed to determine the exact vitamin balance. The oral mucosa is very resistant to normal skin, i.e. it reacts “later” than the body skin. This can be observed especially in children who have, for example, a nut allergy.

A rash in the elbow occurs more quickly than an aphthae in the mouth. Nevertheless, the mucous membrane of the mouth can react with inflammation in case of severe allergies. For example, gluten is a trigger in patients with proven celiac disease (gluten intolerance).

In addition, connections between aphthae and food intolerances have often been observed. Such are for example walnuts, hazelnuts, tomatoes or citrus fruits. The reaction of the body by means of aphthae or similar inflammations is a kind of defence mechanism: if something is not tolerated in the mouth, it should certainly not be allowed to continue into the gastrointestinal tract and cause more serious problems there.