12/02/2026
Tinea capitis is a superficial dermatophyte infection of the scalp hair follicles and surrounding skin, predominantly affecting children. Below is a dermatologist-level, structured overview:
๐ Etiology
Caused by dermatophyte fungi, mainly:
Trichophyton tonsurans (anthropophilic; common in urban epidemics)
Microsporum canis (animal contact)
Trichophyton violaceum
Microsporum audouinii
Transmission: direct human contact, fomites (combs, hats), animals.
๐ Pathogenesis
Dermatophytes invade the stratum corneum and hair shaft keratin.
Patterns of invasion:
Endothrix: spores inside hair shaft (e.g., Trichophyton)
Ectothrix: spores coat hair surface (e.g., Microsporum)
Leads to hair fragility and breakage.
๐ Clinical Types
1. Non-inflammatory
Gray patch: scaly alopecic patches with broken hairs
Black dot: hairs broken at scalp surface
Diffuse dandruff-like scaling
2. Inflammatory
Kerion: boggy, tender plaque with pustules and crust
Risk of scarring alopecia
3. Favus
Yellow cup-shaped crusts (scutula)
Chronic, may cause permanent alopecia
๐ Clinical Features
Patchy alopecia
Scaling
Pruritus (variable)
Cervical/postauricular lymphadenopathy
Broken hairs (โcomma hairs,โ โcorkscrew hairsโ on dermoscopy)
๐ Diagnosis
Clinical + Dermoscopy
Broken hairs
Black dots
Comma/corkscrew hairs
Woodโs lamp
Green fluorescence in Microsporum infections
Mycology
KOH microscopy
Fungal culture (gold standard)
PCR (if available)
๐ Differential Diagnosis
Alopecia areata
Seborrheic dermatitis
Psoriasis
Trichotillomania
Bacterial folliculitis
๐ Treatment
โ ๏ธ Topicals alone are insufficient โ systemic therapy required.
Systemic antifungals
Griseofulvin (first line in many children)
20โ25 mg/kg/day (microsize) for 6โ8 weeks
Preferred for Microsporum
Terbinafine
Weight-based dosing
4โ6 weeks
Better for Trichophyton
Alternatives:
Itraconazole
Fluconazole
Adjunctive topical therapy
Selenium sulfide 2.5% shampoo
Ketoconazole shampoo โ Reduce spore shedding
Kerion management
Short course oral corticosteroids (controversial but used to reduce inflammation and scarring)
Continue systemic antifungal
๐ Complications
Scarring alopecia (especially kerion/favus)
Secondary bacterial infection
Transmission to contacts
๐ Prevention & Public Health
Screen household contacts
Treat asymptomatic carriers
Avoid sharing hair tools
Pet examination if zoophilic source suspected
