Dermatophyte infections may be diagnosed clinically. However, speciation via fungal culture and proof of mycologic cure via serial fungal culture may aid patient care.
Confirm diagnosis of onychomycosis (fungal nail disease) and tinea capitis (fungal scalp infection) prior to treatment if possible.
Limited tinea corporis (body) infection can usually be managed with topical therapy alone. Systemic therapy is preferred for tinea capitis (scalp), tinea barbae (beard), tinea manuum (hands), and onychomycosis (nails).
Most fungal infections of the skin are mild. However, in cases of immunocompromise, fungi can sometimes cause severe disease.
Superficial fungal infection with varying presentation depending on site. Dermatophytes are fungal organisms that require keratin for growth. These fungi can cause superficial infections of the hair, skin, and nails. Dermatophytes are spread by direct contact from other people, animals, soil, and from fomites.
History and exam
Key diagnostic factors
- scaling scalp lesions
- patchy alopecia
- erythematous, scaling skin lesions with central clearing
- erythematous, scaling rash with follicular pustules in beard or mustache
- erythematous, annular patches on face
- vesicles and scaling of hands
- fissuring, maceration, and scaling in the interdigital spaces of the fourth and fifth toes
- chronically, scaly, hyperkeratotic plantar skin with erythema of the soles, heels, and sides of the feet
- folliculitis with nodules
Other diagnostic factors
- thickened nail with subungual hyperkeratosis, onycholysis, and white-yellow to brown discoloration
- small, white speckled patches on the surface of the nail plate with crumbling nail
- black-dot alopecia
- milky white nail plate
- area of leukonychia in the proximal nail plate
- exposure to infected people, animals, or soil
- exposure to fomites, including hat, combs, hairbrushes, and upholstery
- chronic topical or oral corticosteroid use
- diabetes mellitus and other metabolic disorders
- occlusive clothing
- hot, humid weather
- frequenting public bathing areas while barefoot
- deformities of the feet
- recurrent trauma to the skin
- contact sports
- atopic dermatitis
- positive family history
- peripheral vascular disease
1st investigations to order
- potassium hydroxide (KOH) microscopy
Investigations to consider
- fungal culture
- polymerase chain reaction (PCR)
- Wood lamp exam (ultraviolet light)
- reflectance confocal microscopy
tinea barbae, tinea manuum, or Majocchi granuloma
tinea faciale, tinea corporis, tinea cruris, or tinea pedis
tinea unguium (onychomycosis)
Antonella Tosti, MD
Professor of Clinical Dermatology
Dermatology and Cutaneous Surgery
University of Miami Health System
AT received honorarium and travel reimbursement from Valeant, PharmaDerm, and Polichem, and is on the speaker bureau for PharmaDerm.
Dr Antonella Tosti would like to gratefully acknowledge Dr Keira L. Barr and Dr Barry L. Hainer, the previous contributors to this topic.
KLB declares that she has no competing interests. BLH is on the speaker bureaus for the vaccine programs of Merck and Sanofi-Pasteur pharmaceutical companies.
Nanette Silverberg, MD
Clinical Professor of Dermatology
Columbia University College of Physicians and Surgeons
New York City
NS declares that she has no competing interests.
Christina M. Gelbard, MD
Department of Dermatology
Health Science Center of Houston
CMG declares that she has no competing interests.
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