Impetigo

Impetigo (also known as school sores) is a very common skin infection which most GPs see every week. Although most common in school age children, the condition also affects adults.

Highly contagious (spread by touch), Impetigo is caused by infection with the bacterium Staphylococcus aureus. This causes classic lesions which are red at first but rapidly develop a characteristic golden crust. As the lesions are itchy and spread easily, it is common to see many sores on patients. Sometimes the skin blisters (bullous impetigo) or is related only to skin pores (follicular impetigo). Occasionally impetigo can lead to more serious infections so it is important to have it treated.

There are many reasons why people catch impetigo. Most commonly it occurs through contact with another infected person.

Other sources include minor skin scratches and massage (bacteria can be forced into the pores). It is usually very difficult to identify a particular source for the condition in any individual patient.

Treatment is simple, requiring application of antibiotic cream and, for larger or multiple lesions, oral antibiotics. Keeping the lesions dry is very important as bacteria spread most quickly in warm, moist environments.

Alternative treatments that have been tried for impetigo include astringents (alcohol, tea tree oil) and antiseptics (iodine, chlorhexidine, triclosan) but they are ineffective so cannot be recommended. We advise you to avoid the various plant extract products, none of which have proven benefits and application of which may increase the depth and spread of infection.

As the condition is so easy to spread, patients should stay away from nurseries and schools until they have dried up (or until they can be covered easily by clothing) and should not swim until they have healed completely (usually 1-2 weeks depending on the severity of the initial infection).

This lesion, which shows the characteristic redness and golden crusting was on the cheek of a small child. It had only been present for three days but there were already several other patches. It started as a small red area which grew rapidly (it is about 2cm across in the picture) and had already spread by the time the golden crusting became evident.

A single small area like this can usually be treated effectively with antibiotic cream. With more appearing though, it was necessary to use oral antibiotics.

Not all spots are so easy to diagnose as this one so if you have any concerns, please contact your doctor.