Aphthae are very painful, suddenly appearing ulcers with a diameter of one to 30 millimeters. The cause is still not fully understood.

The condition is harmless

They come and go all by themselves. However, this can take up to 14 days. An inflamed oral mucosa, hormonal fluctuations or stress are suspected causes. A vitamin B-12 deficiency could also be the cause of the painful inflammation. Aphthae are not contagious.

When you should see a doctor

If aphthae are very extensive, recur repeatedly and are accompanied by aching limbs or fever, you should see a doctor. This is because a certain form of skin cancer, known as squamous cell carcinoma, looks almost exactly the same. The pain can be treated with mouthwashes, sprays and creams.