Skin Infections - Impetigo/School Sores
- Impetigo (or school sores) is characterised by small infectious blisters, which later develop a honey coloured scab like crust.
- Highly contagious skin infection, most common in infants and school children.
- Often starts at the site of a minor skin injury e.g. graze, insect bite or scratched eczema, although it can also develop in healthy skin.
- More common in hot, humid weather, conditions of poor hygiene or close physical contact.
- Can become a recurrent problem within families and households.
- Most commonly caused by Staphylococcus aureus and Streptococcus pyogenes.
- Treatment with a topical or oral antibiotic is recommended as although not serious in itself can lead to serious complications.
- Impetigo generally presents with pustules and round, oozing patches which increase in size each day. There may be clear blisters, which rupture to form a golden yellow crust. It most often occurs on exposed areas such as the face and hands, or in skin folds, particularly the axillae.
- Systemic signs are not usually present, however if the infection is extensive, fever and regional lymphadenopathy may occur.
Impetigo is diagnosed clinically and swabs for micro-biological analysis are not usually required unless there is recurrent infection, treatment failure or a community outbreak.
For small localised patches of impetigo, topical treatment is recommended initially. Mupirocin cream applied for seven days is a suitable choice (NB Fucidin second line due to increased background resistance). Crusts should be gently removed before applying the cream.
Oral antibiotics should be used for extensive disease or systemic infection or when topical treatment fails.
- For seven days is a suitable choice as it is effective against S. aureus and S. pyogenes.
- Dose PO 50mg/kg/day in four divided doses up to a max. 500mg/dose on an empty stomach.
A simple guide for flucloxacillin dosage is:
- <2 years Flucloxacillin 125mg/5ml 2.5ml qid
- 2-5 years Flucloxacillin 125mg/5ml 5ml qid
- >5 years Flucloxacillin 250mg/5ml 5ml qid (using 50mg/kg/day as a cross check).
- Remember flucloxacillin is often not palatable in the liquid form.
- may be used for people who are allergic to penicillins.
- PO 40 mg/kg/day in four divided doses up to a max. 500mg/dose with or without food.
Broad spectrum antibiotics such as amoxicillin clavulanate are inappropriate because the organisms are usually known and are susceptible to narrow spectrum antibiotics.
If there is a history of MRSA infection empirical therapy should be guided by previous susceptibility data.
Advice for patients with impetigo
- To remove crusted areas:
- If patients wish to remove crusted areas, soak a clean cloth in a mixture of half a cup of white vinegar in a litre of tepid water. Apply this compress to affected areas for about ten minutes several times a day and then gently wipe away crust. Topical antibiotic can then be applied. Note: bullous impetigo should not be lanced.
- To prevent the spread of infection:
- Children should stay away from day-care or school until the lesions have crusted over or they have received at least 24 hours of antibiotic treatment. This may be less important for older children (e.g. secondary school) because they may be less likely to spread the infection through touching each other.
- Cover the affected areas and wash hands after touching patches of impetigo or applying antibiotic cream or ointment.
- Avoid close contact with other people.
- Use separate towels, flannels, clothing and bathwater until the infection has cleared. Disinfect linen and clothing by hot wash, hot dry or ironing.
- Use hand sanitisers and/or careful washing with household soap and water, several times daily.
Recurrent and Community outbreaks of Impetigo
- Recurrent infection and community outbreaks of impetigo may result from the nasal carriage of causative micro-organisms or from fomite colonisation e.g. bed sheets, towels and clothing that may be shared.
- If nasal carriage is suspected (as in recurrent infection), a nasal swab should be taken to confirm this. A topical antibiotic (such as Mupirocin - Fucidin second line due to increased background resistance) may be applied inside each nostril, three times per day for seven days. All household members and close contacts should also be considered.
Last updated : Thursday, May 18, 2017
Next review date : Friday, May 18,2018
Disclaimer: This site is intended to be flexible and frequently updated. While every effort has been made to ensure accuracy, all information should be verified.