Tinea CapitisAbdullatiff Sami Al-RashedBlock 4.1 (Dermatology Week)College of Medicine, King Faisal UniversityAl-Ahsa, Saudi Arabia

Case

A 3-year-old boy presents with a 3-week history of a circular scalp area of hair loss and flaky skin.

He attends daycare and is provided with a sleep mat for an afternoon nap, which is not exclusively for his use.

The scalp lesion is not itchy, but has not gone away with an anti-dandruff shampoo. There are no other skin lesions present.

Definition

• Tinea capitis is a fungal infection of the scalp that most often presents with pruritic, scaling areas of hair loss.

• Several synonyms are used, including ringworm of the scalp and tinea tonsurans.

Epidemiology

• Most common among toddlers and school age children.

• Much more common in blacks than in whites.

Etiology

• Tinea capitis is a dermatophyte infection.

• Dermatophytes are filamentous fungi in the genera Trichophyton, Microsporum, and Epidermophyton that infect keratinized tissue of skin, hair, or nails.

 

Etiology

• Organisms in the These genera causes Tinea Capitis:

Etiology

Etiology varies from country to country and from region to region:

Transmission

Person-to-person, animal-to-person, via fomites.

Spores are present on asymptomatic carriers, animals, or inanimate objects.

Clinical presentation

Non- inflammatory infection

Partial alopecia, often circular in shape, showing numerous broken-off hairs, dull gray from their coating of arthrospores.

Fine scaling with fairly sharp margin.

Infammatory response minimal, but massive scaling.

Clinical presentation

Black dot

Broken off hairs near the scalp give appearance of “dots”.

Tends to be diffuse and poorly circumscribed.

Low-grade folliculitis may be present.

Clinical presentation

kerion

Inflammatory mass in which remaining hairs are loose.

Characterized by boggy, purulent, inflamed nodules, and plaques

Usually painful; drains pus from multiple openings, like honeycomb.

thick crusting with matting of adjacent hairs.

Frequently, associated with lymphadenopathy.

Clinical presentation

Favus

Early cases show perifollicular erythema and matting of hair.

Later, thick yellow adherent crusts (scutula)composed of skin debris and hyphae that are pierced by remaining hair shafts.

Fetid odor. Shows little tendency to clear

spontaneously. Often results in scarring alopecia

History

History

Physical Exam and Investigations

Physical Exam and Investigations

Examination of the affected area with a Wood's light can help identify tinea capitis in patients with some ectothrix

infections and favus.

Ectothrix infections secondary to M. canis often exhibit green-

yellow fluorescence.

T. tonsurans does not fluoresce.

Wood’s light

Diagnosis

skin scales contain hyphae and arthrospores. Ectothrix: arthrospores can be seen surrounding the hair shaft. Endothrix: spores within hair shaft. Favus: loose chains of arthrospores and airspaces in hair shaft

Direct Microscopy ”potassium hydroxide”

Growth of dermatophytes usually seen in 10-14 days.

Rule out bacterial infection, usually S. aureus or GAS.

Fungal Culture Bacterial Culture

Differential Diagnoses

Treatment

Treatment

Adjunctive interventions:• Antifungal shampoo : Selenium sulfide

5-10 ml on wet scalp, 2 applications each week for 2 weeks will provide control.

Prognosis

• The prognosis of tinea capitis is excellent, with complete clearance occurring in most patients after a course of treatment.

• Complete hair regrowth occurs in most children with hair loss.

• Patients with chronic or severe infections (eg, kerion, favus) have the greatest risk for permanent scarring alopecia.

Reference