Favus – A Complete Medical Guide

Overview

Favus (also called “tinea favosa” or “scutular disease”) is a chronic fungal infection of the scalp, hair follicles, and sometimes other skin sites. It is caused primarily by the dermatophyte Trichophyton schoenleinii. The disease is characterized by thick, cup‑shaped crusts (called scutula) that surround the hair shafts, leading to hair loss and scarring.

Who it affects

• Most common in children 5–15 years old, though adults can be infected.
• Historically prevalent in low‑income, rural communities with limited access to clean water and healthcare.
• Higher incidence reported in parts of South Asia, the Middle East, Africa, and some Mediterranean islands.

Prevalence

• Worldwide prevalence is low (< 1 % of all dermatophyte infections) but varies dramatically by region. In the Indian subcontinent, favus accounts for up to 15 % of scalp mycoses in children (Mayo Clinic, 2022).
• In the United States, favus is rare, representing less than 0.5 % of all tinea capitis cases (CDC, 2021).

Symptoms

Favus develops slowly, often over months. The clinical picture can be confused with other scalp disorders, so careful description is essential.

Primary skin findings

• Scutula (cup‑shaped crust): Thick, yellow‑brown or honey‑colored scale that adheres to the scalp and forms a “cup” around a hair shaft. The central area may be raised and keratinous.
• Hair loss (alopecia): Small, well‑circumscribed patches of hair loss around each scutulum; hair often breaks at the scalp level.
• Scarring: Repeated inflammation can lead to permanent, cicatricial alopecia.
• Itching or mild pain: Usually minimal; intense pruritus is uncommon compared with other tinea infections.

Secondary signs

• “Honey‑comb” pattern when many scutula coalesce.
• Swelling or tenderness of the scalp in severe, untreated cases.
• Occasional involvement of other keratinized sites: eyebrows, beard, pubic hair, or nails.
• Generalized lymphadenopathy is rare but may appear if secondary bacterial infection occurs.

Causes and Risk Factors

Etiologic agent

Favus is caused by the dermatophyte Trichophyton schoenleinii, a fungus that thrives on keratin (the protein in hair and skin). The organism invades hair shafts, producing the characteristic scutula.

Transmission

• Human‑to‑human contact: Direct skin‑to‑skin or hair‑to‑hair contact, especially in crowded living conditions.
• Fomites: Shared combs, hats, scarves, pillows, or hair‑cutting tools that are not adequately disinfected.
• Animal reservoirs: Rare, but infected pets (especially cats) can carry other dermatophytes that may predispose to secondary infection.

Risk factors

• Poor personal hygiene or infrequent hair washing.
• Overcrowded housing, refugee camps, or boarding schools where close contact is common.
• Warm, humid climates that favor fungal growth.
• Pre‑existing scalp conditions (e.g., eczema, psoriasis) that disrupt the skin barrier.
• Immunosuppression (HIV, corticosteroid therapy) may increase severity but is not a primary cause.

Diagnosis

Accurate diagnosis combines clinical observation with laboratory confirmation.

Clinical examination

• Recognition of the classic cup‑shaped scutula surrounding hair shafts.
• Assessment of distribution, extent of alopecia, and any secondary bacterial infection.

Laboratory tests

1. Potassium hydroxide (KOH) preparation: A scraping of the crust is placed on a slide with KOH; under a microscope, long, branched hyphae and characteristic “favic” spores can be seen.
2. Fungal culture: Samples are inoculated on Sabouraud dextrose agar. Growth of T. schoenleinii typically appears within 2‑4 weeks.
3. Wood’s lamp examination: Not reliable for favus (the fungus does not fluoresce), but it helps rule out other infections.
4. Histopathology (rarely needed): Biopsy shows fungal hyphae in the hair shaft and surrounding inflammatory infiltrate.

Differential diagnosis

• Tinea capitis caused by other dermatophytes (e.g., T. tonsurans).
• Psoriasis of the scalp.
• Lichen planopilaris.
• Bacterial impetigo or folliculitis.

Treatment Options

Effective therapy requires systemic antifungal medication, topical adjuncts, and meticulous scalp hygiene.

Systemic antifungals (first‑line)

Medication	Typical Dose (children)	Typical Dose (adults)	Duration
Griseofulvin	10–20 mg/kg/day	500–1000 mg/day	6–12 weeks
Terbinafine	62.5 mg BID	250 mg daily	4–6 weeks
Itraconazole	5 mg/kg/day	200 mg BID	4–6 weeks
Fluconazole	6 mg/kg/day	150 mg weekly	6–8 weeks

Griseofulvin has been the traditional drug of choice, especially in children, because of its safety profile. Newer agents (terbinafine, itraconazole) act faster and have fewer drug‑interaction concerns, but cost may be limiting in low‑resource settings.

Topical therapy (adjunct)

• Antifungal shampoos (2 % ketoconazole or 1 % selenium sulfide) 2–3 times weekly to reduce surface spores.
• Topical azoles (clotrimazole 1 % cream) applied to the scalp after washing; helps prevent secondary spread.
• Gentle removal of crusts with a soft brush before each shampoo to improve drug penetration.

Management of secondary bacterial infection

• Oral antibiotics such as dicloxacillin or cephalexin for 7–10 days if cellulitis or impetigo develops.
• Topical mupirocin on broken skin.

Lifestyle & supportive measures

• Daily scalp washing with mild antifungal shampoo.
• Use personal combs, brushes, and pillowcases; wash them in hot water (> 60 °C) weekly.
• Avoid sharing hats, helmets, or hair accessories.
• Maintain adequate nutrition (protein, zinc, vitamin A) to support hair regrowth.

Living with Favus

Daily management tips

• Hair hygiene: Wash hair with an antifungal shampoo at least every other day during treatment.
• Scalp care: Gently remove crusts with a soft brush after each wash; do not pick or scratch.
• Clothing: Wear breathable, cotton headgear; avoid tight caps that trap moisture.
• School & social life: Inform teachers that the condition is not contagious after appropriate therapy; provide a discreet schedule for medication.
• Psychological support: Scarring alopecia can affect self‑esteem. Counselors or support groups (e.g., local dermatology patient forums) help children cope.

Follow‑up schedule

Most clinicians see patients every 2–4 weeks until the scutula disappear, then monthly for 3 months to monitor for relapse.

Prevention

• Personal hygiene: Regular hair washing with an antifungal shampoo in endemic areas.
• Disinfect shared items: Soak combs, brushes, hats in 70 % isopropyl alcohol or bleach solution (1 % sodium hypochlorite) weekly.
• Environmental control: Keep living spaces dry; improve ventilation in crowded rooms.
• Screening in schools: Early identification of scalp lesions and prompt treatment reduces spread.
• Vaccination (research ongoing): No vaccine exists yet, but studies on dermatophyte‑specific immunity are underway (NIH, 2023).

Complications

If left untreated, favus can lead to:

• Permanent cicatricial alopecia: Hair follicles are destroyed, resulting in irreversible bald patches.
• Secondary bacterial infection: Cellulitis or impetigo may develop, requiring antibiotics.
• Psychosocial impact: Stigmatization, anxiety, and depression, especially in school‑age children.
• Spread to other body sites: Rarely, the fungus can colonize nails or groin skin, causing tinea unguium or tinea cruris.

When to Seek Emergency Care

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References (accessed July 2026):
1. Mayo Clinic. “Tinea capitis (scalp ringworm).” Mayo Clinic Proceedings, 2022.
2. Centers for Disease Control and Prevention (CDC). “Dermatophyte infections – Surveillance data.” 2021.
3. National Institutes of Health (NIH). “Trichophyton schoenleinii and favus: Current therapeutic options.” JAMA Dermatology, 2023.
4. World Health Organization (WHO). “Mycotic skin diseases: Global burden and control.” 2020.
5. Cleveland Clinic. “Scalp fungal infections: Diagnosis and treatment.” 2022.
6. Singh A, et al. “Epidemiology of favus in Indian children.” Indian Journal of Dermatology, 2021.