A13. Fungal diseases of the skin and its appendages

Diagnosis of fungal infections
- KOH preparation -> hyphae/yeasts visible under microscope
  - KOH dissolves keratin
- Culture
- Wood-light – green fluorescence UV lamp
Treatment of fungal infections
- Terbinafine – for dermatophytoses
- Fluconasol – for candida
- Itraconazole – for candida, dermatophytoses
- Ketoconazole – for Malassezia (pityrasis versicolor)
Epidermomycoses
- By dermatophytes
- Risk factors
  - Children
  - Immunocompromised
  - Diabetes
- Clinical features
  - Pruritus
  - Scaling
  - Erythema
- Treatment
  - Topical antifungals
    - Terbinafine
    - Azoles
  - Oral antifungals
    - For immunocompromised persons
    - Terbinafine
    - Itraconazole
- Tinea facialis – face
- Tinea corporis – body
- Tinea cruris – inguinal area
- Tinea manuum – hands
  - Usually affects two feet and one hand (syndrome)
  - Because the person scratches the feet with the dominant hand
- Tinea pedis – feet
Onychomycoses
- Discoloured and brittle nails
- Candida
- Tinea unguium
- Treatment
  - Terbinafine
  - Itraconazole
Trichomycosis
- Tinea capitis – scalp
  - Dandruff
  - Smooth areas of hair loss
- Kerion – very inflamed abscess-like mass
- Favus – yellow crust
Candida
- Albicans most common
- Risk factors
  - Immunosuppression
  - Diabetes
  - Antibiotic therapy
- Skin infections
  - Oral candidiasis
  - Angular cheilitis
  - Vulvovaginal candidiasis
  - Balanitis
  - Intertrigo – infection of the skin folds
  - Interdigital candidiasis
  - Diaper rash
  - Chronic mucocutaneous candidiasis
    - Congenital impaired T-cell function
- Clinical features
  - Pruritic erythematous plaque
  - White layer – on mucous membranes, genital organs
- Systemic
  - Candida sepsis
    - Fever that doesn’t improve with antibiotics
  - Invasive candidiasis
Pityriasis versicolor
- Risk factors
  - Hot, humid environment
  - Excessive sweat
- Clinical features
  - Hypomelanotic macules
- Treatment
  - Topical ketoconazole cream
  - Ketoconazole shampoo
Cryptococcosis
- Immunocompromised patients
- Cutaneous cryptococcosis
  - Molluscum contagiosum-like papules
- Can also cause pneumonia and meningitis
- Cryptococcal meningitis
- Treatment
  - Fluconazole
  - Amphotericin
  - Flucytosine
Aspergillosis
- Immunocompromised patients
- Necrotizing nodules
- Abscess