Fungal Disease

Dermatophyte (Tinea)

• Common label for three types of fungus (Microsporum, Epidermophyton, Trichophyton)
• Presentation
  • Red annular scaly pruritic patch or plaque with central clearing and active border
  • Consider confirmation with KOH preparation or culture if appearance atypical or prior to oral treatment
• Subtypes
  • Tinea corporis (ringworm)
  • Tinea capitis (scalp)
  • Tinea cruris (jock itch)
  • Tinea pedis (athlete's foot)
  • Tinea unguium (onychomycosis)
  • Tinea manuum (commonly “one-hand, two-feet” involvement)
  • Tinea barbae
  • Tinea incognito (altered appearance of dermatophyte infection caused by topical steroids)
• Topical antifungals (azoles, allylamines, ciclopirox, butenafine, tolnaftate)
  • Ketoconazole (Ketoderm) 2% cream once daily
  • Terbinafine (Lamisil)1% cream daily-BID
  • Ciclopirox (Loprox) 1% cream BID

Note: Nystatin not effective for dermatophyte infections (only treats candida)

• Consider oral antifungals (eg. Fluconazole 150-200mg PO weekly, Terbinafine 250mg PO daily, Itraconazole, Griseofulvin) if
  • Tinea capitis, onychomycosis, severe pedis (eg. mocassin-type)
  • Multiple regions or extensive
  • Refractory to topical

Yeast (Malassezia)

Pityriasis versicolor (formerly Tinea versicolor)

• Hypo or hyper-pigmented macules on trunk and upper extremities
• Responds well to topical treatment (antifungal, selenium sulfide, zinc pyrithione) but commonly recurs (can consider prophylaxis)

Seborrheic dermatitis

• Greasy scaly ill-defined plaques in areas rich in sebaceous glands (scalp, face, upper trunk, intertriginous areas)
• Treatment
  • Antifungal shampoos (selenium sulfide 2.5%, ketoconazole 2%, or ciclopirox 1%)
    • Alternative shampoos (coal tar, sulfur, zinc)
    • Use daily until remission (usually 2-4 weeks), then weekly to prevent relapse
  • Consider keratolytics if thick scales (salicylic acid, lactic acid, urea, propylene glycol)
  • Consider topical corticosteroid for pruritus or inflammation

Yeast (Candida)

Oropharyngeal candidiasis (thrush)

• Treatment
  • Nystatin 500,000 units PO QID

Intertrigo

• Combination of both infectious (fungal, bacterial) and inflammatory
• Treatment
  • Dry environment to minimize maceration/re-infection
  • Consider topical antifungals, topical antibiotics, avoid steroids (risk of skin atrophy)
    • eg. Ciclopirox 1% cream BID, Terbinafine 1% cream or spray solution daily , Ketoconazole 2% cream daily

Deep Fungal Infections

Majocchi's granuloma

• Deep folliculitis presents as scaly plaque with pustules and nodules
• Treat with oral antifungal 4-6w

Kerion

• Presents as boggy pus-filled lump surrounded by alopecia
• Fungal abscess often misdiagnosed as bacterial infection
• Treat with oral antifungal 6-8w minimum

Nail Fungal Infections

Onychomycosis

• DDx
  • Psoriasis (nail pitting, oil drop sign)
  • Bacterial infection - Pseudomonas aeruginosa (black/green nail)
  • Dermatitis/Eczema
  • Lichen Planus
  • Viral warts
  • Onycholysis
  • Onychogyphosis (elderly nail thickening and scaling)
  • Trauma
• Treatment not mandatory
  • Consider treatment if repeated cellulitis, risk factors for cellulitis (diabetes, immunosuppression), nail pain, discomfort
  • Prior to treatment obtain samples of the subungual debris and nail clippings
    • Fungal culture
    • KOH preparation or PAS stain (if positive can begin treatment)
  • Terbinafine 250mg PO daily (x6w for fingers, x 12w for toes) or topical if drug interactions or patient's preference
    • ALT at baseline and repeat q4-6w
• Prevention (of recurrence)
  • Treat tinea pedis
  • Wear cotton socks, frequent changes
  • Keep feet dry
  • Protect feet in shared areas
  • Improve health conditions (diabetes, smoking)