Impetigo is a superficial skin infection with crusting caused by the bacteria streptococci and / or staphylococci. Ecthyma is an ulcerative form of impetigo.
Impetigo may result from any type of break in the skin that becomes infected with these bacteria. General risk factors seem to be a moist environment, poor hygiene or chronic colonisation of the nostrils with staphylococci. Methicillin-resistant Staphylococci aureus (MRSA) has been isolated in about 20% of recent cases of impetigo.
How common is it?
Impetigo affects approximately 1% of children.
What causes it?
'Nonbullous impetigo' typically presents as clusters of pustules that rupture and develop a honey-coloured crust (that oozes, and then dries from the cut or scratch). 'Bullous impetigo' is similar except that the pustules typically enlarge rapidly to form bullae. The bullae burst and expose larger bases, which become covered with honey-coloured varnish or crust. 'Ecthyma' is characterized by small, purulent, shallow, punched-out ulcers with thick, brown-black crusts and surrounding skin reddening.
Impetigo and ecthyma cause mild pain or discomfort. Itching is common; scratching may spread infection, inoculating adjacent and nonadjacent skin.
What's the outcome?
Impetigo will normally resolve without the need for treatment within two to three weeks. Antibiotic creams are normally used to treat the infection, to minimise the risk of the condition spreading.
Most people will no longer be contagious after 48 hours of antibiotic treatment or once their sores have dried up and healed.
Complications of impetigo are very rare. They include the infection spreading to the lymph nodes (lymphadenitis) or to a deeper layer of skin (cellulitis). Very rarely the infection can also spread to the kidneys, though this occurs in less than 1% of cases.
Treatment
Impetigo can normally be successfully treated using topical antibiotics.
Prevention
As impetigo is very contagious it is important to take hygiene precautions to stop the bacteria spreading and prevent other people catching it. The advice below should help prevent the spread of infection.
- Keep children off nursery, playgroup or school until the sores have stopped blistering or crusting, or until 48 hours after starting treatment
- Do not share flannels, sheets or towels with infected people, and wash them at a high temperature after use
- Wash the sores with soap and water and cover them loosely with a gauze bandage or clothing
- Do not touch the sores
- Wash hands frequently
- Avoid contact with newborn babies until the risk of contagion has passed (which is when any rash has crusted over or after at least 48 hours of treatment with antibiotics)
Impetigo is normally not serious, though it is important to take precautions to avoid spreading it to other people, especially newborn babies. These include carefully washing hands after touching the affected areas of skin and not sharing towels or bed linen, especially pillow cases.
The use of ERADICIL to disinfect the laundry could further decrease the opportunity for the infection to be spread or to re-infect a patient who has recovered from the disease.