Dermatophytosis

Background

• Common fungal infection of the skin, hair and nails
• Mode of transmission via direct contact to the organisms (eg. using unwashed wrestling mats)
• These dermatophytes are filamentous fungi that live off the keratin

Clinical Features

Subtypes of infections include:

• Tinea coporis (ringworm)
  • Body except for feet, groin, face, scalp hair or beard hair
  • Clinical manifestation:
    • Pruritic, circular scaly patch or plaque --> central clearing --> annular plaque
• Tinea pedis
  • Foot
  • Clinical manifestation:
    • Pruritic
    • Erosions
    • Scales
    • Bullous
• Tinea cruris
  • Groin
  • Clinical manifestation:
    • Erythematous patch on proximal inner thigh --> central clearing with sharp borders and vesicles
    • Scrotum typically spared
• Tinea capitis
  • Scalp hair
  • Clinical manifestation:
    • Scaly patches with alopecia
• Tinea unguium (Dermatophyte onchomycosis)
  • Nail
  • Clinical manifestation:

Differential Diagnosis

Tinea pedis

• Interdigital Candida infection
• Erythrasma
• Atopic dermatitis
• Chronic contact dermatitis
• Acute palmoplantar eczema
• Palmoplantar psoriasis
• Pitted keratolysis
• Juvenile plantar dermatosis
• Keratolysis exfoliativa
• Keratodermas
• Acute palmoplantar eczema
• Acute contact dermatitis
• Palmoplantar pustulosis
• Scabies

Tinea cruris

• Inverse psoriasis
• Erythrasma
• Seborrheic dermatitis
• Candidal intertrigo

Tinea corporis

• Subacute cutaneous lupus erythematosus (SCLE)
• Granuloma annulare
• Erythema annulare centrifugum

Evaluation

KOH prep for diagnosis

Management

Tinea coporis

• Topical antifungals (azoles, allylamines, butenafine, ciclopirox, and tolnaftate)
• Oral antifungals for those who fail topical treatment

Tinea pedis

• Topical antifungals
• Oral antifungals (terbinafine, itraconazole, or fluconazole)

Tinea cruris

• Topical antifungals

Tinea capitis

• 1st line
  • Griseofulvin
  • Terbinafine

Tinea unguium

• Mild to moderate
  • 1st line
    • Oral terbinafine
    • Topical efinaconazole, amorolfine, tavaborole, and ciclopirox
• Moderate to severe
  • Terbinafine, itraconazole

References

https://www.uptodate.com/contents/dermatophyte-tinea-infections?source=search_result&search=dermatophytosis&selectedTitle=1~150#H68628070

https://www.uptodate.com/contents/onychomycosis-epidemiology-clinical-features-and-diagnosis?source=search_result&search=tinea%20unguium&selectedTitle=2~15#H522098449

https://www.uptodate.com/contents/onychomycosis-management?source=search_result&search=tinea%20unguium&selectedTitle=1~15

https://www.uptodate.com/contents/tinea-capitis?source=search_result&search=tinea%20capitis&selectedTitle=1~39