Pathophysiology
- Dermatophytes: Three genera — Trichophyton, Microsporum, Epidermophyton — produce keratinases to digest keratin
- Fungi colonize the stratum corneum. Rarely invade deeper in immunocompetent individuals
- Tinea corporis (ringworm): Annular lesion with raised, erythematous, scaly border and central clearing
- Tinea pedis (athlete's foot): Most common dermatophyte infection. Scaling and fissuring between toes. Portal for cellulitis
- Tinea capitis: Scalp infection with patchy hair loss. Kerion (boggy inflammatory mass) in severe cases
- Tinea cruris (jock itch): Scaly patches in inguinal folds. Spares the scrotum (distinguishes from candidiasis)
- Tinea unguium (onychomycosis): Nail thickening, discoloration, crumbling. Very difficult to eradicate
Signs and Symptoms
Hallmark Indicators
- Corporis: Annular red patch with raised scaly border and central clearing. Pruritic
- Pedis: Scaling, maceration, fissuring between toes (especially 4th-5th web space)
- Capitis: Patches of hair loss with scaling. "black dot" pattern from broken hairs
- Cruris: Red, scaly, well-defined patches in groin with advancing border
- Unguium: Thickened, yellowed, crumbling nails
- Pruritus is the most common symptom across all types
Red Flags and Rule-Outs
- All tinea infections are contagious — local contraindication
- Tinea pedis as portal of entry: Untreated athlete's foot can lead to lower leg cellulitis
- Distinguish tinea cruris (spares scrotum) from candidiasis (involves scrotum)
- Widespread or treatment-resistant tinea: Refer for oral antifungals. May indicate immunocompromise
- KOH prep / Wood lamp: Medical diagnostic standards
MT Considerations
- Local contraindication: All active tinea — avoid the affected area and surrounding margins
- Contagious: Transmitted by direct contact and fomites (linens, floor mats)
- IPAC: Hot water laundering of all linens. Sanitize table, face cradle, and equipment
- Tinea pedis awareness: Check clients' feet during lower extremity work. Cracking between toes may be undiagnosed
- Cellulitis counseling: Advise that untreated tinea pedis can be a portal for bacterial cellulitis
- Nail involvement: Persistent local contraindication for hand/foot massage until resolved
- Referral: Widespread, recurrent, or resistant tinea needs medical management
CMTO Exam Relevance
- Tinea = fungal. "ringworm" is NOT a worm
- All tinea infections are contagious — local contraindication
- Tinea pedis is the most common portal of entry for lower leg cellulitis
- Tinea cruris spares the scrotum (distinguishes from candidiasis)
- KOH prep and Wood lamp fluorescence are diagnostic standards
Key Takeaways
- Tinea infections are superficial fungal infections caused by dermatophytes digesting keratin
- Named by body site: corporis, pedis, capitis, cruris, unguium
- Ringworm is NOT a worm — fungal infection with characteristic ring-shaped lesion
- All tinea infections are contagious — local contraindication. Strict IPAC required
- Tinea pedis is the most common portal of entry for cellulitis of the lower leg