Tinea pedis

Background

• The most common dermatophyte infection
• Most commonly in young men
• Caused by T. rubrum, T. interdigitale, and E. floccosum
• Spread through direct contact (locker rooms, near swimming pools)
• Manifests as interdigital, hyperkeratotic, or vesiculobulbous eruption, rarely ulcerative
• Often accompanied by other forms of tinea

Tinea Types

• Tinea capitis (head)
• Tinea corporis (body)
• Tinea pedis (foot)
• Tinea cruris (groin)

Clinical Features

Interdigital tinea pedis

Hyperkeratotic tinea pedis

• Interdigital tinea pedis: pruritic, erythematous erosions between the toes, can be associated with painful fissures (most common type)
• Hyperkeratotic tinea pedis (mocasin-type): A mocasin distribusion of hyperkeratosis on the soles and side of the feet
• Vesiculobullous tinea pedis (inflammatory): Pruritic or painful vessicles or bullae with underlying erythema often affecting the medial foot
• Ulcerative tinea pedis: Interdigital erosions or ulcers (uncommon and usually associated with secondary bacterial infection)

Differential Diagnosis

• Interdigital tinea pedis
  • Erythrasma
  • Interdigital Candida infection

• Hyperkeratotic tinea pedis
  • Atopic dermatitis
  • Chronic contact dermatitis
  • Acute palmoplantar eczema
  • Palmoplantar psoriasis
  • Pitted keratolysis
  • Juvenile plantar dermatosis
  • Keratolysis exfoliativa
  • Keratodermas

• Vesiculobullous tinea pedis
  • Acute palmoplantar eczema
  • Acute contact dermatitis
  • Palmoplantar pustulosis

Foot diagnoses

Acute

• Foot and toe fractures
• Subtalar dislocation
• Metatarsophalangeal joint sprain (turf toe)
• Acute arterial ischemia
• Calcaneal bursitis

Subacute/Chronic

• Diabetic foot infection
• Peripheral artery disease
• Plantar fasciitis
• Trench foot
• Ingrown toenail
• Paronychia
• Tinea pedis
• Morton's neuroma
• Diabetic neuropathy

Evaluation

• Generally a clinical diagnosis
• Diagnosis can by confirmed by detecting segmented in hyphae in skin scrapings when put in KOH prep

Management

Coverage for Trichophyton and Epidermophyton and all treatment should be at lease 1 week past resolution of lesions

Topical Therapy

Applies to Tinea corporis, pedis, cruris, and manus

Must use a topical therapy for 7-10days beyond resolution of lesions

• Topical antifungal treatment for all except tinea capitis
• Terbinafine 1% BID x2-3weeks or
• Clotrimazole 1% BID x2-3weeks or
• Ketoconazole 1% BID x2-3weeks

Capitis

• Griseofulvin 500mg-1000mg PO once daily (20-25mg/kg/d)
  • Usually requires 8wk of treatment
• Terbinafine for 2-4 weeks is as effective of 6-8 weeks of griseofulvin
  • 62.5mg/day in children <20kg
  • 125mg/day in children 20-40kg
  • 250mg/day in children >40kg
• Selenium sulfide or ketoconazole shampoos are adjunct treatment
• Children can return to school during treatment

Kerion

• Oral griseofulvin, itraconazole, or terbinafine for 6-8 wks
• Cephalexin 40mg/kg/d in 4 divided doses in addition to systemic antifungal treatment if there is evidence or high risk of bacterial secondary infection
• Ketoconazole shampoo, isolated towels decrease spread to household members

Tinea corporis

First line should be topical therapy. For refractory cases or severe bullous disease the below anti-fungals are all equivalent options.

• Fluconazole 150mg (6mg/kg) PO once a week x 2 weeks or
• Itraconazole 200mg (5mg/kg) PO daily q12hrs for 1 week or
• Griseofulvin 500-1000mg (20mg/kg) PO daily for 2-4 weeks

Disposition

• Outpatient treatment

See Also

• Tinea