Makindo Medical Notes

🦠 Cutaneous fungal infections are among the most common dermatological presentations worldwide. They affect keratinised tissues (skin, hair, nails) and are caused by dermatophytes, yeasts, and non-dermatophyte moulds. 💡 Usually superficial, but they may cause significant morbidity if untreated. Correct diagnosis is essential, as therapy differs by organism and site.

📖 About

• Also called dermatophytoses or "tinea" infections.
• Involve keratinised structures: stratum corneum, hair shafts, and nails.
• Main organisms:
  • Dermatophytes: Trichophyton, Epidermophyton, Microsporum
  • Yeasts: Candida, Malassezia
  • Moulds: e.g. Scopulariopsis
• Transmission via direct human contact, animals (zoophilic), or contaminated fomites.

🔬 Common Types

• Tinea corporis: “ringworm” of the body – annular lesions with raised, scaly edges and central clearing.
• Tinea capitis: scalp infection – patchy alopecia, scaling, “black dot” hairs; severe inflammation = kerion.
• Tinea pedis (athlete’s foot): interdigital scaling, moccasin-type hyperkeratosis, or vesicular eruption.
• Tinea cruris (jock itch): erythematous plaques in groin/thighs, typically sparing the scrotum.
• Tinea unguium (onychomycosis): nail thickening, yellow-brown discolouration, onycholysis.
• Candidiasis: erythematous moist plaques in skin folds, oral thrush, periungual inflammation.
• Pityriasis versicolor: hypopigmented or hyperpigmented patches with fine scale due to Malassezia.

🧩 Clinical Features

• Itching, erythematous annular advancing edges, and scaling.
• Hair infection: broken hairs, alopecia, kerion (boggy inflammatory plaque).
• Nail infection: subungual debris, brittle/crumbling nail plate.
• Candidiasis: erythema with satellite pustules in moist areas.
• Pityriasis versicolor: fine scaling with colour variation (hypo/hyperpigmented), often worse in summer.

🧪 Diagnosis

• Clinical examination: classic “ringworm” morphology.
• KOH microscopy: hyphae or budding yeasts in skin scrapings/nail clippings.
• Culture (Sabouraud agar): species identification for resistant or atypical cases.
• Wood’s lamp: fluorescence in some species (e.g. Microsporum = green).
• Dermoscopy: “comma hairs” or “corkscrew hairs” in tinea capitis.

📊 Comparison Table

💊 Management

• Topical antifungals: clotrimazole, terbinafine, ketoconazole for localised disease.
• Systemic antifungals: itraconazole, terbinafine, fluconazole for hair/nail infections or refractory cases.
• Adjuncts: keep areas dry, avoid occlusion, treat household contacts/animals if infected.
• Monitor for recurrence: common in nails and pityriasis versicolor.

⚠️ In the UK, nail and scalp fungal infections usually require oral antifungals prescribed after mycological confirmation. GPs should send clippings/scrapings before systemic therapy. Immunocompromised patients may have atypical or widespread disease.