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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Dermatophyte infection by body site

Dermatology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull

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.
  • Take skin scrapings from the active untreated edge, plucked abnormal hairs for scalp disease and nail clippings plus subungual debris before systemic treatment.
For localised skin infection, terbinafine 1% cream once or twice daily for one to two weeks is usually effective; follow the exact product and site licence.
  • Confirm nail fungus before oral therapy and distinguish dermatophyte species where drug choice differs, especially scalp infection.
  • Avoid steroid–antifungal combination prescribing without a defined inflammatory indication and short plan; steroid alone produces tinea incognito.
  • Dry toe webs, change socks and footwear, avoid shared towels and treat infected household members or animals when confirmed rather than disinfecting indiscriminately.

    • 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.

    Kerion

    A tender boggy scalp plaque with pustules and loose hairs threatens follicular destruction and scarring alopecia.

    Investigation priorities

    01
    Skin scraping for microscopy and cultureFirst step

    Confirm dermatophyte at an active plaque edge before uncertain or systemic treatment.

    Management branches

    Localised glabrous skinUse topical therapy correctly

    A limited corporis, cruris or pedis pattern is typical and hair, nail and severe host risk are absent.

    1. Scrape when uncertain or steroid-modified, then apply topical terbinafine across the lesion and one to two centimetres beyond its edge.
    2. Complete the product-specific one-to-two-week course, continue hygiene and treat fissures or eczema without potent steroid monotherapy.
    3. If no response, verify diagnosis, application, reinfection and mycology before extending or switching treatment.

    Key medicines

    Terbinafine 1% creamApply a thin layer once or twice daily to clean dry affected skin and a small surrounding margin for one to two weeks according to site and product directions.Avoid eyes and mucosa, stop for significant irritation, and do not use topical treatment alone for scalp, beard-hair or established nail infection.
    Clotrimazole 1% creamApply thinly two or three times daily for at least two weeks and continue according to product advice until symptoms resolve.Local irritation can occur; avoid eyes and check excipients, and reassess diagnosis if a correctly applied course fails.
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    Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
    Sources

    Sources and review status

    National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

    • NHS ringwormBody-site recognition, spread, treatment and referral.
    • British Association of Dermatologists fungal nail infectionsDiagnostic confirmation and systemic-treatment considerations.
    • Lamisil 1% cream SmPCTopical terbinafine sites, frequency and duration.
    • Clotrimazole 1% cream SmPCTopical azole application and safety.

    Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

    Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom