Impetigo, folliculitis and skin abscess — Rapid

Synopsis

Distinguish superficial impetigo and folliculitis from a drainable abscess, use proportionate topical or oral therapy and manage recurrence, transmission and invasive complications.

Non-bullous impetigo causes thin-walled vesicles or pustules that rupture into characteristic golden or honey-coloured crusts.
Bullous impetigo produces flaccid fluid-filled blisters from toxin-producing Staphylococcus aureus and usually needs oral treatment.
Folliculitis is a superficial pustule centred on a hair follicle; many limited cases improve with hygiene and removal of friction or occlusion.
A furuncle involves the deeper follicle, while a skin abscess is a tender fluctuant collection whose definitive treatment is incision and drainage.
For localised non-bullous impetigo, NICE first offers hydrogen peroxide 1% cream two or three times daily for five days when suitable.
If antiseptic is unsuitable, fusidic acid 2% three times daily for five days is a topical option; reserve mupirocin for suspected or confirmed fusidic-acid resistance.
For widespread non-bullous or bullous impetigo, flucloxacillin 500 mg four times daily for five days is NICE first-choice adult oral treatment.
Do not routinely combine topical and oral antibiotics for impetigo, and do not use antibiotics alone to treat a fluctuant abscess that needs drainage.

Key red flags

Pain out of proportion, bullae, anaesthesia, necrosis or crepitus suggests necrotising infection.

Painful eye movement, proptosis, ophthalmoplegia or visual change suggests orbital cellulitis.

Hypotension, confusion, tachypnoea or rapidly spreading erythema indicates invasive infection and possible sepsis.

A large, deep, recurrent or perineal abscess may reflect hidradenitis, fistula, foreign body or immune compromise.

Carbuncle, bacteraemia or persistent fever in diabetes or immune suppression lowers the threshold for admission.

Infants with widespread blistering or systemic illness require urgent paediatric assessment for staphylococcal toxin disease.

Drainable abscess

A tender fluctuant nodule with pointing, pus or an ultrasound-defined cavity indicates a collection needing incision and drainage.

Surrounding invasive disease

Spreading warmth, lymphangitis, fever, hypotension or disproportionate pain extends the problem beyond a simple superficial lesion.

Investigation priorities

Full skin and anatomical examinationFirst step

Define superficial versus deep disease, extent, drainable pus, lymphangitis and critical-site involvement.

Management branches

LOCAL IMPETIGOUse antiseptic before antibiotic

Non-bullous impetigo is localised and the patient is systemically well.

Confirm the crusted superficial pattern and exclude herpes, eczema flare, ecthyma, cellulitis and bullous or widespread disease.
Offer hydrogen peroxide 1% cream two or three times daily for five days when suitable and explain gentle crust cleansing and hand hygiene.
If antiseptic is unsuitable, use fusidic acid 2% three times daily for five days, reserving mupirocin for fusidic-acid resistance risk.
Review worsening or non-response and obtain a swab before changing treatment when feasible; do not add oral antibiotics routinely.

Key medicines

Hydrogen peroxide 1% creamApply a thin layer two or three times daily for five days to localised non-bullous impetigo when the preparation is suitable.Avoid contact with eyes and mucosa, stop for significant irritation and use another pathway for bullous, widespread, deep or systemically unwell disease.

Fusidic acid 2% creamApply a thin layer three times daily for five days when localised non-bullous impetigo requires a topical antibiotic and antiseptic is unsuitable.Avoid repeated or prolonged courses because resistance develops; obtain a swab for recurrence or failure and do not combine routinely with oral antibiotics.

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