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This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
Key points
- Named by site: corporis (body), pedis (feet), cruris (groin), capitis (scalp), unguium (nails)
- Classic: annular erythematous scaly plaque with central clearing and advancing border
- Skin scraping for KOH microscopy and fungal culture from advancing edge
- Skin: topical terbinafine cream OD-BD for 1-2 weeks
- Tinea capitis and unguium ALWAYS need ORAL antifungal — terbinafine or griseofulvin
Overview
Dermatophyte infections are caused by fungi (Trichophyton, Microsporum, Epidermophyton) that metabolise keratin. Named by site. Classic ringworm appearance: annular plaque with central clearing and advancing scaly border. Tinea capitis primarily affects children (Trichophyton tonsurans commonest in UK). Tinea pedis is the commonest portal of entry for lower limb cellulitis.
Epidemiology
Extremely common — tinea pedis affects 15-25% of population. Risk factors: warm/moist environments, communal bathing, diabetes, immunosuppression, occlusive footwear.
Clinical Features
Symptoms
Tinea corporis: annular scaly patches with central clearing
Tinea pedis: itchy, scaly skin between toes (4th/5th web space)
Tinea capitis: scalp scaling, alopecia patches, kerion
Tinea unguium: thickened, discoloured, dystrophic nails
Signs
Annular plaque with peripheral scale, advancing border, central clearing
Tinea pedis: interdigital maceration, moccasin pattern scaling
Tinea capitis: broken hairs, black dots, kerion (boggy inflammatory mass)
Onychomycosis: distal subungual discolouration, onycholysis, hyperkeratosis
Investigations
First-line
Skin scraping for mycologyFrom advancing edge — KOH microscopy (rapid) and fungal culture (4-6 weeks)
Nail clippingsConfirm fungal infection before starting oral antifungals
Second-line
Wood's lampMicrosporum fluoresces green. T. tonsurans does NOT
Management
NICE CKS + BAD Guidelines1
Skin (corporis, cruris, pedis) — topical
- Terbinafine 1% cream OD-BD for 1-2 weeks (most effective)
- OR clotrimazole 1% cream BD for 4 weeks
2
Tinea capitis — ORAL required
- Topicals alone are INEFFECTIVE
- Terbinafine 250 mg OD 4 weeks (Trichophyton) or griseofulvin (Microsporum, children)
- Adjunctive antifungal shampoo (ketoconazole 2%)
3
Tinea unguium — ORAL required
- Confirm with mycology BEFORE treatment
- Terbinafine 250 mg OD: 6 weeks fingernails, 12 weeks toenails
- Itraconazole pulse therapy as alternative
Complications
- Cellulitis: Tinea pedis is commonest entry point for lower limb cellulitis
- Kerion: Inflammatory tinea capitis — risk of scarring alopecia
- Id reaction: Secondary eczematous eruption as immune response to distant fungal infection
UKMLA Exam Tips
- 1Tinea capitis ALWAYS needs oral antifungal — topical alone insufficient
- 2Tinea pedis is key predisposing factor for cellulitis — check between toes
- 3Confirm nail infection with mycology BEFORE prescribing oral terbinafine
- 4Kerion is NOT an abscess — do NOT incise. Treat with oral antifungal
- 5Annular lesion + central clearing + advancing scaly border = ringworm
Put your reading into practice
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regional clinical guidance
Dermatophyte Fungal Infections (Tinea): guidance by region
Recommendations, thresholds and pathways can differ. Open the page written for the jurisdiction you need.
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