Synopsis
Recognise dermatophyte infection by anatomical pattern, obtain mycology when systemic treatment or uncertainty makes it consequential, and match topical or oral therapy to hair, nail, skin and host involvement.
- Tinea corporis is annular with an advancing scaly edge; cruris affects groin folds, pedis affects toe webs or sole, and manuum often produces one dry scaly palm with two affected feet.
- Tinea capitis causes scale, broken hairs, black dots or alopecia and always needs systemic treatment; topical cream alone cannot reach infected hair shafts.
- A boggy pustular kerion risks permanent scarring and needs urgent systemic treatment, bacterial assessment and dermatology input.
Key red flags
Kerion with scarring risk, painful boggy scalp, bacterial superinfection, orbital proximity, extensive disease in immune compromise, diabetic foot ulceration or a rapidly spreading steroid-modified eruption requires urgent or specialist assessment.
A tender boggy scalp plaque with pustules and loose hairs threatens follicular destruction and scarring alopecia.
Investigation priorities
Confirm dermatophyte at an active plaque edge before uncertain or systemic treatment.
Management branches
A limited corporis, cruris or pedis pattern is typical and hair, nail and severe host risk are absent.
- Scrape when uncertain or steroid-modified, then apply topical terbinafine across the lesion and one to two centimetres beyond its edge.
- Complete the product-specific one-to-two-week course, continue hygiene and treat fissures or eczema without potent steroid monotherapy.