Pharmacy First: Impetigo

About this service

Impetigo is a superficial bacterial skin infection caused by Staphylococcus aureus and sometimes Streptococcus pyogenes. It is highly contagious and most common in children, though it can affect any age group. The NHS Pharmacy First pathway covers non-bullous impetigo in children aged 1 year and over and adults who are systemically well.

The pathway has a clear three-tier treatment structure based on how many lesions are present. Localised impetigo (3 or fewer lesions or clusters) is treated topically: hydrogen peroxide 1% cream is first line, and fusidic acid 2% cream is second line for use only when hydrogen peroxide is unsuitable or has not worked. Widespread impetigo (4 or more lesions or clusters) requires oral flucloxacillin.

Bullous impetigo is entirely outside this pathway. It requires referral to a GP and must not be treated under any Pharmacy First PGD. The ability to distinguish non-bullous from bullous impetigo is therefore a core clinical requirement for delivering this service.

Who to offer the service to

Include

• Aged 1 year and over
• Non-bullous impetigo confirmed (see clinical features below)
• Systemically well (not unwell, no fever, no systemic signs)
• NHS eligibility requirements apply

Exclude

• Under 1 year old: outside the Pharmacy First pathway. Refer to GP.
• Pregnancy under 16: excluded. For pregnant individuals aged 16 and over, a separate erythromycin PGD (3e) applies for widespread impetigo.
• Currently breastfeeding with impetigo lesions on the breasts: excluded. If lesions are elsewhere, topical and oral treatments may be used with monitoring and with advice to avoid direct contact between the infant and the lesions.
• Bullous impetigo: refer to GP urgently. Do not treat under any Pharmacy First PGD.
• Severely immunocompromised: refer to GP same day
• Immunosuppressed with widespread impetigo: refer to A&E urgently
• Recurrent impetigo (2 or more episodes in the same year): refer to GP
• Active underlying skin condition that is currently uncontrolled: active eczema, contact dermatitis, scabies, chickenpox, or eczema herpeticum. Refer to GP.
• Failed previous antimicrobial treatment for this episode: refer to GP
• Known MRSA colonisation or infection: refer to GP
• Known liver disease or previous flucloxacillin-associated jaundice (applies to oral flucloxacillin): refer to GP
• Signs of a more serious illness: large blisters, severe swelling, severe pain, spreading redness, or suspected cellulitis or Staphylococcal scalded skin syndrome: refer to A&E urgently
• Systemically unwell: refer to GP or A&E depending on severity
• Sepsis suspected: call 999

How to deliver the service

1. Confirm the diagnosis and exclude bullous impetigo Impetigo presents as small vesicles or pustules that rupture quickly and leave golden or honey-coloured crusts, typically around the nose and mouth or on the limbs. Bullous impetigo is characterised by larger fluid-filled blisters (1-2cm) that persist for 2-3 days before rupturing to leave a thin flat yellow-brown crust. If the lesions look more like blisters than crusts, or if the crust is thin and flat rather than thick and honey-coloured, consider bullous impetigo and refer to GP rather than treating.
2. Count the lesions and determine topical or oral treatment 3 or fewer lesions or clusters: localised impetigo, treat topically. 4 or more lesions or clusters: widespread impetigo, treat orally with flucloxacillin. Check for active underlying skin conditions (active eczema, scabies, chickenpox, eczema herpeticum) which exclude the patient from this pathway. Confirm the patient is systemically well.
3. For localised impetigo: select the correct topical treatment Hydrogen peroxide 1% cream (Crystacide) is first line. Apply three times daily for 5 days. Fusidic acid 2% cream is second line only: use it if hydrogen peroxide is unsuitable (for example near the eyes, or in a patient who cannot stay away from naked flames) or if hydrogen peroxide has been tried and has not worked. Before supplying fusidic acid, ask specifically whether the patient has ever used fusidic acid cream before for any condition. Any previous use of topical fusidic acid is an exclusion due to resistance risk. Fusidic acid is also a fire hazard: do not supply to patients who smoke or who are regularly near naked flames.
4. For widespread impetigo: check interactions before supplying flucloxacillin Check for methotrexate, probenecid, and voriconazole (must not supply under this PGD). Check for warfarin use (INR monitoring advised). Check for liver disease or previous flucloxacillin-associated jaundice (excluded). Confirm penicillin allergy status. Counsel on empty stomach dosing: 1 hour before food or 2 hours after food.
5. Give contagion advice and safety net Impetigo is highly contagious. The patient is no longer contagious 48 hours after starting treatment, or when lesions are healed, dry, and crusted if no treatment is given. Advise: stay away from school or work until no longer contagious, inform the school or nursery, wash hands before and after applying cream, wash flannels, sheets, and towels at a high temperature, and wipe toys with detergent and warm water. Food handlers are required by law to inform their employer immediately. Safety netting: seek urgent help if lesions spread rapidly, blisters appear or enlarge, or the person becomes systemically unwell.

Treatment outcome by presentation

Clinical Features: Non-Bullous versus Bullous Impetigo

Distinguishing non-bullous from bullous impetigo is essential. Bullous impetigo is outside this pathway and requires GP referral.

Treatment Decision by Lesion Count

Count lesions or clusters at assessment. The lesion count determines whether topical or oral treatment is appropriate.

Flucloxacillin Doses for Widespread Impetigo (four times daily, empty stomach, 5 days)

Take 1 hour before food or 2 hours after food. For penicillin allergy, use clarithromycin dosed by weight using BNF for Children.

Recording and submission

• Complete the consultation record contemporaneously on PharmOutcomes.
• Key information to record:
  • Patient name, date of birth, NHS number
  • Lesion count and distribution: how many lesions or clusters and where
  • Lesion type confirmed: non-bullous (crusted) or bullous (blistered). If bullous: referral documented.
  • Systemically well confirmed
  • Active underlying skin condition excluded
  • Recurrent impetigo excluded (first episode this year or none in the past year)
  • Treatment selected and rationale: topical (H2O2 or fusidic acid) or oral (widespread)
  • For fusidic acid: previous use excluded and fire risk assessed
  • For flucloxacillin: drug interactions checked, liver disease excluded, penicillin allergy confirmed
  • Medicine supplied: name, strength, dose, frequency, duration, quantity, batch number, expiry date
  • Contagion advice given (school/work exclusion, hygiene, food handler notification)
  • Safety netting provided

Key takeaways

• Count the lesions first: 3 or fewer means topical treatment (hydrogen peroxide first line, fusidic acid second line only); 4 or more means oral flucloxacillin. Bullous impetigo (blisters, thin flat crust) is outside this pathway entirely and requires GP referral.
• Fusidic acid is second line only, requires no previous use for any indication, and must not be supplied to patients who smoke or are near naked flames due to fire risk.
• Impetigo is highly contagious: patients must stay away from school or work until 48 hours after starting treatment, and food handlers must notify their employer by law.

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