Background Information
Definition
Highly contagious, superficial bacterial skin infection
2 main types of impetigo:
- Non-bullous impetigo (~70% of cases): characterised by small erythematous papules, vesicles and pustules that rapidly evolve into oozing superficial erosions that form honey-colored crusts (on drying), which is the hallmark of non-bullous impetigo.
- Bullous impetigo (~30% of cases): characterised by flaccid bullae that contain yellow fluid
Aetiology
Most common: Staphylococcus aureus
Rarely: Streptococcus pyogenes (GASGroup A streptococcus.)
Guidelines
Investigation and Diagnosis
Clinical diagnosis, investigations not routinely needed.
Only consider swabs (of exudate/pus) for culture and sensitivities if:
- Failed to respond to treatment
- Recurrent / widespread impetigo
- Doubt about diagnosis
- MRSA suspected
Management
Conservative Care
Advice on:
- Impetigo is usually self-limiting (heals in 7-21 days without treatment)
- Hygiene measures
- Wash affected areas with soap and water
- Avoid touching or scratching patches of impetigo
- Wash hands regularly, including after touching affected areas
- Cover affected areas where possible
- Not share towels, facecloths, and other personal care products
- Clean equipment, including toys and play equipment, daily
- Wash clothing and bedding on the hottest available setting (at least 60 degrees)
- Clothing and bedding should be washed and changed daily during the first few days of treatment
- Exclusion recommendations (childcare facilities / school / work)
- Until all lesions are crusted and healed, or
- Until 48 hours after starting antibiotic treatment
Pharmacological Management
Choice of route and drug depends on the type and extent of impetigo.
Notes on suspected/confirmed MRSA infection
- It is advised to seek further microbiology specialist input to determine antibiotic choice
- Of the available topical antibiotics, topical mupirocin is active against MRSA
Non-bullous Impetigo
Choice depends on the extent of impetigo:
| Extent of impetigo | Management |
|---|---|
| Localised disease | Offer topical hydrogen peroxide 1%
|
| Widespread disease | Offer topical or oral (preferred if systemically unwell) antibiotics for 5 days
|
Topical hydrogen peroxide should NOT be used if impetigo is around the eyescan cause significant irritation, chemical conjunctivitis, and potential ocular injury . Use topical antibiotics instead.
If the 1st line measures are not effective / inappropriate, step up according to this ladder:
- Topical hydrogen peroxide
- Topical antibiotics
- Oral antibiotics
This means that if hydrogen peroxide did not work → step up to topical antibiotics. If topical antibiotics did not work → step up to oral antibiotics
Bullous Impetigo / Systemically Unwell
Offer oral antibiotics for 5 days:
- 1st line: flucloxacillin
- Alternative (i.e., penicillin allergy): clarithromycin or erythromycin (preferred in pregnancy)
References
NICE Guideline Impetigo: antimicrobial prescribing
NICE CKS Impetigo