Synopsis
Distinguish common contagious bacterial, mite and dermatophyte infections by morphology and distribution, use short evidence-based topical or systemic treatment, coordinate household and school advice and escalate bullous, crusted, scalp or invasive disease promptly.
- Non-bullous impetigo produces thin-roofed vesicles that rupture into golden crusts, often around nose and mouth; bullous impetigo forms larger flaccid blisters and is more likely to need oral treatment.
- For localised non-bullous impetigo in a systemically well child, offer hydrogen peroxide 1% cream two or three times daily for 5 days; use a short topical antibiotic when antiseptic is unsuitable.
- Widespread non-bullous or bullous impetigo usually needs oral flucloxacillin for 5 days using current child dosing; do not combine topical and oral antibiotics routinely.
- Scabies causes severe nocturnal itch, burrows and papules on finger webs, wrists, axillae, waist or genital region; infants can have scalp, face, palms and soles involved.
- Treat the child and all household or close physical contacts on the same day, even if contacts are asymptomatic, with two correctly applied permethrin 5% treatments 7 days apart unless an alternative is needed.
- Apply scabicide to the whole body, include scalp and face in children under 2 years while avoiding eyes and mouth, cover under nails and reapply to washed hands during the treatment interval.
- Itch can persist for several weeks after successful scabies treatment; new burrows or progressive lesions after correctly repeated household therapy suggests ongoing infestation or reinfection.
- Tinea corporis has an enlarging annular scaly edge with central clearing, while tinea capitis causes scale, broken hairs, alopecia, lymph nodes or an inflammatory kerion.
- Skin dermatophyte infection usually responds to topical terbinafine or an azole for the product-specific course, but scalp and nail disease need systemic therapy and fungal sampling.
- A boggy painful kerion needs urgent specialist treatment to prevent scarring alopecia; avoid topical corticosteroid alone on an undiagnosed annular eruption because it can mask and spread tinea.
Key red flags
Neonatal bullae, widespread tenderness or peeling can indicate staphylococcal scalded skin syndrome and needs admission.
Fever, severe pain, rapid spread, lymphangitis or haemodynamic change suggests cellulitis or invasive bacterial infection.
Thick widespread crusting in an immunocompromised or institutionalised child suggests highly contagious crusted scabies.
A painful boggy scalp swelling with hair loss is kerion and risks permanent scarring without systemic treatment.
Eye, mucosal or extensive facial blistering requires consideration of herpes or severe mucocutaneous disease.
A child with recurrent extensive fungal infection, poor growth or unusual organisms needs immune and systemic assessment.
Haematuria, oedema or hypertension after impetigo suggests post-streptococcal glomerulonephritis.
A tender boggy scalp plaque with pustules, alopecia and nodes requires urgent systemic antifungal assessment to prevent scarring.
Investigation priorities
Distinguish bacterial crust, mite distribution and fungal border and identify symptomatic or asymptomatic close contacts.
Management branches
Golden crusts or flaccid bullae are present without a deeper skin emergency.
- Use hydrogen peroxide 1% for localised non-bullous disease, or a 5-day topical antibiotic when antiseptic is unsuitable.
- Use oral flucloxacillin for widespread non-bullous or bullous disease, selecting current child dose and allergy alternative.
- Avoid routine topical-plus-oral combination, review after the course and culture recurrent or failed infection.