When to use antibiotics for impetigo in primary care, and which ones?

Antibiotic prescribing for impetigo in primary care: when and which agents

• Localised non-bullous impetigo around which hydrogen peroxide 1% cream is unsuitable: offer a short course of a topical antibiotic. Fusidic acid 2% is the first-choice topical antibiotic in this setting; if fusidic acid resistance is suspected or confirmed, use mupirocin 2% instead.
• Widespread non-bullous impetigo: offer a short course of either a topical or an oral antibiotic. If topical treatment is unsuccessful, offer an oral antibiotic. The decision should be individualized, considering resistance data, patient preferences and practicalities, possible adverse effects, and previous use. Repeated doses or extended use of the same topical antibiotic should be avoided due to antimicrobial resistance.
• People who are systemically unwell or at high risk of complications (for example, immunocompromised or coexisting skin conditions) should be offered an oral antibiotic.
• If meticillin-resistant Staphylococcus aureus (MRSA) is suspected or confirmed, consult a local microbiologist.

Antibiotic choices

• Topical antibiotics: Evidence supports fusidic acid as the first-choice topical antibiotic for non-bullous impetigo when hydrogen peroxide 1% cream is unsuitable. If fusidic acid resistance is suspected or confirmed, mupirocin (2%) should be used.

Oral antibiotics (non-pullular non-bullous impetigo)

• For adults aged 18 years and over: Prescribe flucloxacillin 500 mg four times daily for 5 days.
• If the person is allergic to penicillin or if flucloxacillin is unsuitable (for people who are not pregnant): Prescribe clarithromycin 250 mg twice daily for 5 days. For severe infections, the dosage can be increased to 500 mg twice daily.
• If the person is pregnant and allergic to penicillin: Prescribe erythromycin 250 mg to 500 mg four times daily for 5 days.
• If meticillin-resistant Staphylococcus aureus (MRSA) is suspected or confirmed: Consult a local microbiologist.

Oral antibiotic dosing in children and young people (under 18 years)

• Prescribe flucloxacillin (oral solution or capsules):
  • Age 1 month to 1 year — 62.5 mg to 125 mg four times daily for 5 days.
  • Age 2–9 years — 125 mg to 250 mg four times daily for 5 days.
  • Age 10–17 years — 250 mg to 500 mg four times daily for 5 days.
• If the child or young person is allergic to penicillin or if flucloxacillin is unsuitable (for example, if an oral solution is unpalatable and the child is unable to swallow capsules): Prescribe clarithromycin.
• Under 8 kg: 7.5 mg/kg twice daily for 5 days.
• 8–11 kg: 62.5 mg twice daily for 5 days.
• 12–19 kg: 125 mg twice daily for 5 days.
• 20–29 kg: 187.5 mg twice daily for 5 days.
• 30–40 kg: 250 mg twice daily for 5 days.
• Ages 12–17 years — 250 mg twice daily for 5 days.

Notes

• If MRSA is suspected or confirmed, consult a local microbiologist.