What are the various types of tinea infections and how is each managed?

Types of Tinea Infections and Management

Tinea infections are classified by body site, and management depends critically on location: tinea capitis requires oral antifungals (topical therapy alone fails), while tinea corporis, cruris, and pedis typically respond to topical agents unless extensive or resistant.

Classification of Tinea Infections by Body Site

Tinea infections are dermatophyte fungal infections named according to the anatomic location affected 1, 2:

• Tinea capitis (scalp)
• Tinea corporis (body/trunk)
• Tinea cruris (groin)
• Tinea pedis (feet)
• Tinea manuum (hands)
• Tinea unguium/onychomycosis (nails)
• Tinea barbae (beard area)

The most common causative organisms are Trichophyton rubrum, Trichophyton tonsurans, Trichophyton interdigitale, Microsporum canis, and Epidermophyton species 1, 3.

Management by Type

Tinea Capitis (Scalp)

Oral antifungal therapy is mandatory—topical therapy alone does not achieve clinical or mycological cure 4.

First-line treatment selection depends on the causative organism:

• For Trichophyton species (T. tonsurans, T. violaceum, T. soudanense): Terbinafine is more efficacious 4

  • <20 kg: 62.5 mg daily for 2-4 weeks
  • 20-40 kg: 125 mg daily for 2-4 weeks

  • 40 kg: 250 mg daily for 2-4 weeks

• For Microsporum species (M. canis, M. audouinii): Griseofulvin is more effective 4

  • <50 kg: 15-20 mg/kg/day for 6-8 weeks

  • 50 kg: 1 g daily for 6-8 weeks

The reason for this organism-specific efficacy is pharmacologic: terbinafine is not excreted in sweat or sebum of prepubertal children and cannot be incorporated into hair shafts effectively, failing to reach scalp surface arthroconidia in Microsporum infections 4.

Second-line therapy: Itraconazole 50-100 mg daily or 5 mg/kg/day for 2-4 weeks (effective against both Trichophyton and Microsporum) 4.

Critical management points:

• Start treatment empirically if kerion or cardinal signs present (scale, lymphadenopathy, alopecia) while awaiting mycology 4
• Treatment endpoint is mycological cure, not clinical improvement—repeat sampling until clearance 4
• Screen all family members and close contacts for T. tonsurans cases (>50% may be affected) 4
• Children on appropriate therapy can attend school 4

Tinea Corporis (Body) and Tinea Cruris (Groin)

Topical antifungal therapy is first-line for localized disease 1, 5.

Topical options (applied once to twice daily for 2 weeks):

• Allylamines (terbinafine): Fungicidal, may have slightly higher cure rates and shorter treatment courses 6, 5
• Azoles (clotrimazole, miconazole, ketoconazole): Fungistatic, effective and inexpensive 5

Oral antifungals indicated when:

• Extensive disease
• Failed topical therapy
• Immunocompromised patients
• Hair follicle involvement 1

Critical pitfall: Avoid combination antifungal-corticosteroid products—only 7-10% appropriate use documented, and these contribute to emerging resistance 7. If inflammation is severe, use an antifungal with inherent anti-inflammatory properties or separate agents temporarily 5.

Tinea Pedis (Feet)

Topical antifungals are first-line for superficial or localized disease 3.

Three clinical forms to recognize:

• Interdigital (most common)
• Hyperkeratotic/moccasin-type
• Vesiculobullous/inflammatory 3

Topical therapy (once to twice daily for 4 weeks with azoles, or 1-2 weeks with allylamines):

• Terbinafine (allylamine)
• Azoles (ketoconazole, clotrimazole)
• Ciclopirox, tolnaftate, amorolfine 5, 3

Oral antifungals reserved for:

• Severe disease
• Failed topical therapy
• Concomitant onychomycosis
• Immunocompromised patients 3

Prevention is essential: T. rubrum persists in hotel rooms, gyms, and public facilities. Patients must wear protective footwear, use antifungal powders in shoes, wear absorbent cotton socks, and discard contaminated footwear 8.

Tinea Unguium/Onychomycosis (Nails)

Oral antifungal therapy is required for nail infections 8.

First-line options:

• Terbinafine 250 mg daily: 6 weeks for fingernails, 12-16 weeks for toenails (generally preferred) 8
• Itraconazole: 200 mg daily for 12 weeks continuously, OR pulse therapy 400 mg daily for 1 week/month (2 pulses for fingernails, 3 for toenails) 8

Second-line: Fluconazole 150-450 mg weekly for 3 months (fingernails) or ≥6 months (toenails) 8

Features predicting treatment failure:

• Nail thickness >2 mm
• Severe onycholysis
• Dermatophytoma (dense white lesion beneath nail requiring debridement)
• Slow nail outgrowth 8

Monitoring: Baseline liver function tests and complete blood count recommended for terbinafine; monitor hepatic function with itraconazole in continuous therapy >1 month 8.

Diagnostic Approach

Clinical diagnosis alone is unreliable—tinea corporis mimics eczema, onychomycosis mimics psoriatic nails or trauma 1.

Confirm diagnosis with:

• KOH wet-mount examination of skin scrapings from active border (point-of-care testing) 3
• Fungal culture when needed for species identification 4
• Wood's lamp examination (limited utility—only some Microsporum species fluoresce) 6

Diagnostic testing is underutilized: <10% of patients receive testing in practice, contributing to inappropriate treatment 7.

Emerging Resistant Tinea

Emerging tinea infections may be more severe and do not respond to first-line topicals or oral antifungals 1. These require prolonged oral therapy and specialized diagnostic testing. Antifungal stewardship—particularly avoiding combination antifungal-corticosteroids—is critical to prevent resistance 1, 7.