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By Bjarne Lühr Hansen PhD, MD and Philipp Skafte-Holm MD, Mentor Institute

Stomatitis is caused by a virus. The illness starts with a fever. After a few days, blisters appear in the mouth. Later, grey-yellow blisters around the lips appear. The child does not want to eat or drink. The illness passes by itself in the course of 10 to 14 days. If your child does not want to drink and becomes drowsy and weak, you must call the doctor immediately.

Stomatitis especially appears with children of the age of 2 to 4 years. The illness begins with a fever (38-39ºC). In the course of 1 to 2 days grey-white blisters appear in the mouth. The gums turn red, swell up and bleed easily. The blisters burst fast and turn into superficial wounds. After a few more days, the blisters spread to the lips and the skin surrounding the mouth. The glands in the throat below the jaws enhance and become sore.

Since the wounds in the mouth hurts, often the child will not eat or drink. It is not of great importance that the child will not eat but the intake of fluid is necessary. If the child does not drink, it will dehydrate and that can be dangerous. If the child is dehydrated, it will stop urinating and become weak and drowsy. It takes around one week before the wounds have healed up so the child can eat and drink normally.

Stomatitis is caused by a certain virus – called herpes type 1 virus. It is the same virus that causes cold sore on the lips. The herpes virus cannot be removed completely when it has first entered the body. The virus is dormant for the most of the time but is triggered in certain situations – for example when you are exposed to cold or sun – and can be a real bother. Typically, the child has stomatitis the first time it is attacked by herpes type 1 virus. The child will thereafter develop a cold sore on the lips when the virus is triggered.

Stomatitis disappears by itself in the course of 1 to 2 weeks.

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Stomatitis infects through the air via spit. It can also infect through objects the child has touched, for example toys.

Day care:
The child is kept at home until the temperature is normal and the child can participate in its usual activities without extra care.


The illness is incurable but there is medication that can soothe the child’s nuisances. For the medication to work the child must begin treatment as fast as possible and no more than 3 days after the illness broke out. Your general practitioner can prescribe the medication. If the child does not drink at all, you can try to administer paracetamol. The paracetamol soothes the pains in the mouth in half an hour and when that time has passed, you may try to get the child to drink.

What can you do?

Often, the child will not eat and therefore it is of extra importance to offer it plenty to drink. Some children prefer cold, others warm drinks – you have to feel your way.

Contact the doctor tomorrow

If the child has a fever and does not want to drink.

Contact the doctor immediately

If the child shows signs of dehydration – meaning that urination stops and the child becomes weak.