Makindo Medical Notes

📖 About

• Very common superficial fungal infection of the scalp.
• Primarily affects children, especially in communities with overcrowding and socio-economic deprivation.

🧬 Aetiology

• Caused by dermatophytes (fungi that invade keratinised tissues).
• Most common: Trichophyton tonsurans (anthropophilic).
• Occasionally: Microsporum canis (zoophilic, spread from cats/dogs 🐱🐶).
• Transmission: direct contact or via fomites (hats, combs, bedding).

🩺 Clinical Features

• Starts as a small papule at the base of a hair follicle → spreads to form a scaly circular plaque (“ringworm”).
• Within the lesion: brittle, broken “exclamation mark” hairs ✂️.
• Confluent patches of alopecia may develop, often itchy.
• Kerion: severe inflammatory reaction → boggy, tender, granulomatous mass studded with sterile pustules.
• Systemic signs may include fever 🌡️ and regional lymphadenopathy.
• Risk of permanent scarring alopecia if untreated.

🔍 Differentials

• Alopecia areata (smooth scalp, no scaling or inflammation).
• Psoriasis or seborrhoeic dermatitis of scalp.
• Bacterial folliculitis or impetigo.
• Discoid lupus erythematosus (scarring alopecia with scaling).

🧪 Investigations

• Wood’s lamp: Microsporum species fluoresce dull green.
• KOH preparation: shows fungal spores and hyphae.
• Culture on Sabouraud medium with antibiotics confirms the species.

💊 Management

• Systemic therapy is essential (topical agents alone are inadequate).
• First-line: Oral Griseofulvin for 6–12 weeks.
• Alternatives: Terbinafine, Fluconazole, or Itraconazole (useful in resistant cases).
• Adjunct: Selenium sulfide or ketoconazole shampoo twice weekly to reduce spore shedding and transmission.
• Public health: treat household contacts if symptomatic, avoid sharing combs, bedding, hats.

📚 References

• British Association of Dermatologists – Clinical Guidelines.
• Oxford Handbook of Clinical Dermatology.
• DermNet NZ – Tinea Capitis