1 Does your child have sores or cracks on or around the lips?

2 Do the sores look like small blisters?

3 Do the sores have honey-coloured crusts?

4 Are the lips and surrounding skin red and cracked?

5 Does your child have red, painful gums?

6 Do the gums bleed when your child brushes his or her teeth?

7 Does your child have creamy yellow or white patches inside the mouth and/or on the tongue?

8 Does your child have one or more shallow, grey, ulcerated patches or blisters in the mouth?

9 Does your child also have blisters on the palms of the hands and the soles of the feet?

10 Does your child have a fever and/or seem generally unwell?

11 Does your child have a sore area inside a cheek or on the side of the tongue?

12

Possible cause Your child may have cold sores, which are caused by previous infection with the herpes simplex virus. After the initial infection, the herpes virus can lie dormant for months or years and may be reactivated by cold weather or exposure to the sun.

Action Cold sores usually clear up on their own. However, over-the-counter antiviral creams may speed up the process if they are used at the first sign of symptoms. To prevent your child from spreading the virus, try to discourage him or her from kissing others while the blisters are present.

13 See your doctor within 24 hours

Possible cause Impetigo, a bacterial skin infection that commonly affects the skin around the mouth, is likely.

Action Your doctor will probably advise you to remove the crusts with cotton wool and warm water. He or she may also prescribe an antibiotic cream to apply to the affected areas or oral antibiotics. Until the infection clears up, your child should use a separate towel and other wash items to avoid spreading the infection. Keep your child away from other children as impetigo is contagious.

14

Possible cause Your child may have lick eczema, a rash around the mouth and lips caused by saliva from excessive licking of the lips or thumb sucking.

Action Twice a day, apply an over-the-counter corticosteroid cream sparingly to the skin around the lips for a few days to reduce the inflammation, then use petroleum jelly to protect the skin. You may be able to help your child give up the habit that is causing the condition by drawing his or her attention to it when it occurs. However, scolding your child about the habit may make it worse.

15

Possible cause Your child may have the gum disease gingivitis, a condition in which the gums become red and swollen. Gingivitis usually develops as a result of poor oral hygiene. Consult your dentist.

Action The dentist will probably scale and polish your child's teeth and advise you on caring for your child's teeth and gums. If the gum disease is severe, the dentist may prescribe antibiotics.

16

Possible cause and action An erupting tooth can cause a tender swelling on the gum (see Teething). Offer a baby a hard, cooled teething ring to chew. Over-the-counter teething gels applied to the gums may help. Give the recommended dose of a painkiller if necessary.

17 See your doctor within 24 hours

Possible cause Oral thrush, a fungal infection, is a possibility. This condition is most common in young babies or in older children whose immunity has been lowered by certain diseases or drug treatments.

Action Your doctor will probably prescribe antifungal gel or drops to clear up the infection. To prevent reinfection, sterilize any dummies, bottle teats, and teething rings that your child uses.

18

Possible cause Your child may have hand, foot, and mouth disease, a mild infection caused by a virus. The blisters on the hands and feet often appear about 48 hours after the ones in the mouth. Consult your doctor.

Action There is no specific treatment for this condition. If the blisters burst and form ulcers, encourage your child to rinse his or her mouth with a solution of bicarbonate of soda. Give your child the recommended dose of a painkiller if necessary (see Relieving a sore mouth). Make sure your child drinks plenty of fluids (see Encouraging your child to drink).

19 See your doctor within 24 hours

Possible causes The most likely cause is infection with the herpes simplex virus, the virus that causes cold sores. When babies or young children have a first infection with this virus they may be unwell and have a very sore mouth. Similar symptoms can be due to other viruses or, in some cases, to prescription drugs.

Action If the child's mouth is so sore that he or she is unable to drink, your doctor may recommend hospital admission. In less severe cases, your doctor will recommend self-help measures (see Relieving a sore mouth). If prescription drugs are thought to be the cause they will be stopped.

20

Possible cause Your child may have mouth ulcers. These often develop for no apparent reason but tend to recur in times of stress or at the site of a minor injury, such as damage from a toothbrush. Mouth ulcers can be painful but are not serious.

Action Rinsing the mouth with a solution of bicarbonate of soda may help relieve the pain (see Relieving a sore mouth). Over-the-counter treatments can also relieve pain and may help the ulcers to heal. If an ulcer does not heal within 10 days or your child has several ulcers at the same time, consult your doctor.

21

Possible cause and action A new or jagged tooth may cause enough friction to make your child's cheek or tongue sore. Take steps to relieve the pain (see Relieving a sore mouth). If the sore persists or appears to be cause by a jagged tooth, consult your dentist, who may be able to smooth a rough edge.

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Consult your doctor if you are unable to make a diagnosis from this chart.

23

Consult your doctor if you are unable to make a diagnosis from this chart.