Basics
Description
Superficial fungal infections of the skin, hair, and nails are characterized by erythema, scaling, changes in color, and pruritus.
Epidemiology
- Dermatophyte infections
- Tinea capitis
- Most common fungal infection in pediatric population
- Occurs mainly in prepubescent children (between ages 3 and 7 years)
- Asymptomatic carriers are common and contribute to spread.
- Tinea corporis is usually seen in younger children or in young adolescents with close physical contact to others (i.e., wrestlers).
- Onychomycosis: Overall prevalence is 0-2.6% in children; often occurs with concomitant tinea pedis or in 1st-degree relatives with infection
- Candidiasis: majority of infants colonized with Candida albicans
- Tinea versicolor: seen in adolescents and young adults
General Prevention
- Measures should be taken to avoid transmission between hosts, including not sharing combs, brushes, hats, etc.
- Hair utensils and hats should be washed in hot, soapy water at onset of therapy.
- Pets should be watched and treated early for any suspicious lesions.
- In patients in whom appropriate therapy has not led to improvement in symptoms, siblings and close contacts should be examined and fungal cultures performed.
- Isolation of hospitalized patient is unnecessary.
Pathophysiology
- Fungal elements (arthroconidia) adhere to stratum corneum or hair shaft. Proteases work to degrade keratin, which allows for invasion of dermatophytes.
- Predisposing factors may include moisture, macerated skin, and immunocompromise.
- Host immune response is usually able to contain infection.
- Inflammatory response is variable; highly inflammatory forms may lead to pustules and kerion (large inflammatory mass) formation.
Etiology
- Varies by geographic region
- Dermatophyte infections
- Tinea capitis: >90% caused by Trichophyton tonsurans in North America; spread from human to human (anthropophilic); increasing incidence of Microsporum canis infection spread from animals such as cats and dogs to humans (zoophilic).
- Tinea corporis: preadolescent children: M. canis, Microsporum audouinii; older children: Trichophyton rubrum, Trichophyton mentagrophytes, T. tonsurans
- Onychomycosis: T. rubrum, T. mentagrophytes
- Candidiasis: usually C. albicans
- Tinea versicolor: Malassezia furfur
Diagnosis
History
- Determine onset and duration.
- Elicit signs and symptoms such as expanding areas of erythema, scaling, or color change with associated pruritus.
- Determine contacts, including exposure to pets.
- Determine if patient is immunocompromised.
- List of medications previously prescribed or used
Physical Exam
- Dermatophyte infections
- Tinea capitis: Presentation varies.
- Round patches of alopecia with erythema or black dots (broken hair shafts at surface of skin)
- Diffusely dry scalp with scaling
- Follicular pustules resembling bacterial folliculitis
- Boggy, tender plaque with follicular pustules or purulent discharge (kerion): represents exaggerated immune response
- Cervical or occipital lymphadenopathy
- Tinea corporis
- One or more, asymmetrically distributed, annular, well-demarcated erythematous scaling plaques with central clearing
- Inflammatory forms may be frankly pustular or vesicular at the borders.
- Lesions may occur anywhere on the body.
- Onychomycosis
- Distal subungual type: invasion of the underlying nail bed and inferior portion of the nail plate, which leads to detachment of the nail plate from the nail bed and subungual thickening and debris with yellowing of the plate
- Proximal subungual type: invasion of the nail unit at the proximal nailfold (most common in HIV patients)
- White superficial type: Superficial infection presents with white plaques on the dorsal nail plate.
- Candidiasis
- Diffuse erythema (often "beefy" red) with sharp, marginated border
- Pinpoint satellite pustules at edge of erythema
- Prefers warm, moist environments
- Favors skinfolds/creases (axillae, groin, below breasts, and, in infants, diaper area)
- Tinea versicolor
- Scaling, oval patches that are either hypo- or hyperpigmented
- Distributed on upper trunk, neck, and proximal arms and in areas where there is high amount of sebum and free fatty acids, which the organism requires; occasionally on face
Diagnostic Tests & Interpretation
Lab
- KOH preparation
- Clean area with alcohol.
- Using a no. 15 scalpel blade, gently scrape the outer edge of the active border, broken off hairs, or subungual debris.
- Place material flat on a glass side in a single layer. Apply coverslip on top.
- Place a few drops of 10-20% KOH to edge of coverslip until space between slide and coverslip is filled, and apply mild pressure.
- Warm slide gently or let sit for 30 minutes.
- Examine slide under microscope at low power under low light.
- Dermatophytes: arthrospores around or within hair shaft; long, branching fungal hyphae with septations
- Candidiasis: budding yeast, pseudohyphae
- Tinea versicolor: short hyphae and clusters of spores ("spaghetti and meatballs")
- Fungal culture
- Obtain specimen with scalpel blade from outer active edge of scaling.
- For scalp, gently rub a wet sterile toothbrush, cytobrush, or cotton-tipped swab over the area of scaling, then plate on fungal medium.
- Results can take up to 4 weeks.
- Some laboratories provide drug susceptibility testing as well as identification of fungus.
Diagnostic Procedures/Other
- Wood's lamp examination (~360-nm wavelength of ultraviolet light): Infected hairs may fluoresce (not useful in skin or nail infections).
- Examine in completely darkened room.
- Ectothrix infections (organisms outside of hair shaft): bright green fluorescence (M. canis and M. audouinii); endothrix infections (organisms inside hair shaft): do not fluoresce (T. tonsurans)
- Tinea versicolor: yellow, copper, or bronze fluorescence
Differential Diagnosis
- Dermatophyte infections
- Dermatologic conditions
- Tinea capitis: seborrheic dermatitis, psoriasis, alopecia areata, trichotillomania, folliculitis, impetigo, atopic dermatitis
- Tinea corporis: herald patch of pityriasis rosea, nummular dermatitis, psoriasis, contact or atopic dermatitis, granuloma annulare
- Onychomycosis: psoriasis, nondermatophyte infection
- Systemic diseases: cutaneous T-cell lymphoma, histiocytosis, sarcoidosis
- Candidiasis
- Dermatologic conditions: contact dermatitis, seborrheic dermatitis, atopic dermatitis, bacterial infection
- Tinea versicolor
- Dermatologic conditions: pityriasis alba, postinflammatory hypopigmentation, vitiligo, seborrheic dermatitis, pityriasis rosea
Treatment
Medication
First Line
- Dermatophyte infections
- Tinea capitis: systemic therapy warranted to penetrate hair shaft
- Oral griseofulvin: 20-25 mg/kg/24 h (max 1 g/24 h) once daily or divided b.i.d. of microsize griseofulvin for 6-8 weeks (10-15 mg/kg/24 h [max 750 mg/24 h] once daily or divided b.i.d. if ultramicrosize form is used), taken with high-fat food (e.g., milk or ice cream) for 6-12 weeks. In addition, topical therapy of 2.5% selenium sulfide or ketoconazole shampoo twice weekly suppresses viable spores. Laboratory monitoring is not needed.
- Tinea capitis with kerion
- Treat for tinea capitis.
- Systemic steroids may be needed to treat significant inflammation.
- Tinea corporis
- Topical azole antifungals (1% clotrimazole, 2% ketoconazole) or 1% terbinafine cream applied twice daily for 2-4 weeks
- Onychomycosis
- Oral terbinafine 3-6 mg/kg/dose (max 250 mg) once daily for 6-12 weeks; can be associated with hepatic failure; avoid use in patients with liver disease. Check liver enzymes before and during treatment.
- Oral itraconazole (adolescent and adult) in weekly pulses for 3-4 months; 200 mg twice daily for 7 days, then off for 3 weeks
- Candidiasis: topical nystatin cream or ointment 3-4 times daily for 7-10 days
- Tinea versicolor: selenium sulfide 2.5% applied to affected skin for 10 minutes. Wash off thoroughly. Apply daily for 7-10 days. Monthly applications may help prevent recurrences.
Second Line
- Dermatophyte infections
- Tinea capitis
- Oral itraconazole: 3-5 mg/kg once daily for 4-6 weeks. May also use oral terbinafine 3-6 mg/kg once daily for 4 weeks or oral fluconazole 5 mg/kg once daily for 4-6 weeks. All of these may be associated with hepatic failure and should be avoided in patients with liver disease. Liver enzymes should be checked before and during treatment.
- Tinea corporis
- Oral griseofulvin 15-25 mg/kg once daily or divided b.i.d. for 4 weeks for persistent or extensive involvement
- Candidiasis
- Oral fluconazole
- 6 mg/kg on day 1, then 3 mg/kg once daily for 2 weeks if poor response to topical therapy
- Tinea versicolor
- Topical azole antifungals (ketoconazole 2% shampoo applied daily for 3 days)
- Oral ketoconazole (adolescent and adult) 200-400 mg once daily for 5-10 days or itraconazole (adolescent and adult) 200 mg once daily for 5-7 days if severe, recurrent, or persistent
Ongoing Care
Follow-up Recommendations
Patient Monitoring
- Monitor for secondary bacterial infection.
- Highly inflammatory lesions (kerion) may require concomitant systemic steroids.
- Repeated infection may indicate a source that needs to be diagnosed and treated (e.g., family member or pet).
Diet
Griseofulvin is better absorbed with a fatty meal and should be taken with foods such as milk, eggs, or ice cream.
Prognosis
- Dermatophyte: Inflammation improves within several days but may take several weeks to completely resolve; nail infections take 6-12 months to show improvement and are prone to recurrence.
- Areas with significant inflammatory component may become scarred and permanently alopecic.
- Candidal skin lesions improve within 24-48 hours and resolve by 1 week.
- Tinea versicolor: Resolution of dyspigmentation may take months to occur.
- Relapses and recurrences are common.
Complications
- Dermatophyte infections
- Secondary bacterial infection
- Kerion formation can lead to permanent alopecia and scarring.
- Candidiasis
- Scarring in severe disease
- Fungemia in immunocompromised host
Additional Reading
- Ameen M. Epidemiology of superficial fungal infections. Clin Dermatol. 2010;28(2):197-201. [View Abstract]
- Andrews MD, Burns M. Common tinea infections in children. Am Fam Physician. 2008;77(10):1415-1420. [View Abstract]
- Baldo A. Mechanisms of skin adherence and invasion by dermatophytes. Mycoses. 2012;55(3):218-223. [View Abstract]
- Elewski BE. Terbinafine hydrochloride oral granules versus oral griseofulvin suspension in children with tinea capitis: results of two randomized, investigator-blinded, multicenter, international, controlled trials. J Am Acad Dermatol. 2008;59(1):41-54. [View Abstract]
- Gupta AK. Superficial fungal infections: an update on pityriasis versicolor, seborrheic dermatitis, tinea capitis, and onychomycosis. Clin Dermatol. 2003;21(5):417-425. [View Abstract]
- Shemer A. Update: medical treatment of onychomycosis. Dermatol Ther. 2012;25(6):582-593. [View Abstract]
Codes
ICD09
- 110.9 Dermatophytosis of unspecified site
- 110.5 Dermatophytosis of the body
- 112.3 Candidiasis of skin and nails
- 110.1 Dermatophytosis of nail
- 111.0 Pityriasis versicolor
- 111.8 Other specified dermatomycoses
- 110.0 Dermatophytosis of scalp and beard
ICD10
- B35.9 Dermatophytosis, unspecified
- B35.4 Tinea corporis
- B37.2 Candidiasis of skin and nail
- B35.1 Tinea unguium
- B35.0 Tinea barbae and tinea capitis
- B36.8 Other specified superficial mycoses
- B36.0 Pityriasis versicolor
SNOMED
- 47382004 Dermatophytosis (disorder)
- 266151007 Dermatophytosis of the body (disorder)
- 49883006 candidiasis of skin (disorder)
- 402134005 Onychomycosis due to dermatophyte (disorder)
- 238443004 Systemic fungal infection affecting skin
- 5441008 Tinea capitis (disorder)
- 266148000 Dermatophytosis of scalp or beard (disorder)
- 56454009 Pityriasis versicolor (disorder)
FAQ
- Q: What is the role of combination topical antifungals and corticosteroids in the treatment of superficial fungal infections of the skin?
- A: Combination products containing high-potency topical steroid antifungals should be avoided. High-potency topical steroids may lead to a decrease in inflammation; however, they can mask the clinical features of tinea infection (so-called tinea incognito) and can allow for rapid expansion of infection. In addition, prolonged use of high-potency topical steroids used particularly in intertriginous areas can lead to side effects such as striae formation and atrophy of the skin.
- Q: What can be done to prevent recurrent tinea versicolor infection?
- A: M. furfur is a normal part of skin flora and lives in lipid-rich areas of skin. Tropical climates, humid environments, and excessive sweating result in infection in adolescents and young adults. Recurrences are common and can be prevented by regular application of selenium sulfide 2.5%. In addition, itraconazole has been shown to be effective in prevention of tinea versicolor. In one study, the recurrence of tinea versicolor was prevented in 88% of patients over a 6-month period using itraconazole 200 mg b.i.d. 1 day per month.
- Q: How can a clinician adequately assess for complete clearance when treating tinea capitis?
- A: At the end of treatment course, a repeat fungal culture should be performed to ensure complete clearance of spores.