Scope of this summary
Immunocompetent and immunocompromised patients with suspected dermatophyte infection of glabrous skin, groin or feet. Scalp, nail and deep dermatophyte infection need different systemic and diagnostic pathways. This page does not supply a universal oral-antifungal regimen.
The Bottom Line
- Confirm an annular, scaly or interdigital eruption in context, but use potassium-hydroxide microscopy, culture or other testing when morphology is atypical, treatment has failed, hair or nail is involved, or resistance is plausible.
- Treat localized skin disease with an appropriate topical antifungal for the product-specific full course and continue skin-drying and footwear or clothing measures that reduce recurrence.
- Do not use topical corticosteroid alone or an antifungal鈥搒teroid combination as a shortcut, because steroids can worsen dermatophyte infection and produce tinea incognito.
- Consider systemic treatment and specialist input for extensive, inflammatory, recurrent or topical-refractory disease, immunocompromise, hair or nail involvement, or a suspected emerging resistant species.
- Reconsider the diagnosis and obtain species or susceptibility support when a correctly used course fails; resistant Trichophyton species and sexually associated TMVII now require deliberate epidemiologic assessment.
Practical clinical workflow
1
Ask about contact sports, household infection, pets, shared showers, occlusive footwear, travel, intimate contact, prior antifungals and any steroid-containing cream; examine nails, scalp and all linked body sites.
2
Scrape the active scaly border for potassium-hydroxide examination when confirmation is needed, and obtain fungal culture or molecular identification through public-health or reference laboratories for severe or suspected resistant disease.
3
Choose a topical antifungal labeled for the site and patient, teach application beyond the visible margin, and address moisture, footwear, socks, towels and simultaneous tinea pedis that can reseed other sites.
4
At follow-up, distinguish slow resolution or post-inflammatory color change from active scale and expansion; confirm adherence and stop inadvertent steroid exposure before escalating.
5
For inflammatory genital, facial or widespread plaques after travel or intimate contact, consider TMVII and coordinate dermatology, infectious-disease or health-department testing and partner counseling.
Safety boundaries and escalation
- A painful rapidly spreading rash, fever, purulence, extensive blistering or immunocompromised host requires urgent assessment for bacterial infection, deep fungal disease or another serious dermatosis.
- Oral antifungals have agent-specific hepatic, interaction, pregnancy and monitoring risks; confirm the organism and use current FDA labeling rather than copying a topical-treatment schedule.
- Tinea capitis requires systemic therapy and can scar; nail involvement is not cured by ordinary topical skin regimens and may be a reservoir for recurrent foot or groin disease.
- Report or seek CDC consultation for unusual severe or resistant dermatophytosis when public-health investigation is indicated, particularly with TMVII or suspected terbinafine-resistant strains.
Localization
CDC emphasizes diagnostic testing, avoidance of steroid creams and awareness of emerging resistant dermatophytes. Local laboratory capacity and health-department reporting pathways vary.
Source documents
Use the linked source documents for complete recommendations, evidence grading, exclusions and implementation detail.
- Centers for Disease Control and PreventionClinical Overview of Ringwormupdated 2024-07-15 路 accessed 2026-08-20view source
- Centers for Disease Control and PreventionTreatment of Ringwormupdated 2026-02-09 路 accessed 2026-08-20view source
- Centers for Disease Control and PreventionTrichophyton mentagrophytes genotype VIIupdated 2026-05-21 路 accessed 2026-08-20view source
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