Tinea capitis

Tinea capitis, a highly contagious disease, typically shows scaly patches of scalp hair loss associated with “black dots”, which represent distal ends of broken hairs 

Presents typically single or multiple patches of hair loss, sometimes with a ‘black dot’ pattern that may be accompanied by inflammation, scaling, pustules, and itching.

Often associated with broken-off hairs.

Uncommon in adults.

Tinea capitis has a greater prevalence in children.

Predominantly seen in pre-pubertal children, more often boys than girls.

Dermatophytosis has been found to be most prevalent in children ages 4 to 11, infecting more males than females.

Low socioeconomic status was found to be a risk factor for Tinea capitis.

Throughout Africa, dermatophytoses are common in hot- humid climates and with areas of overpopulation.

At least eight species of dermatophytes are associated with tinea capitis.

Cases of Trichophyton infection predominate from Central America to the United States and in parts of Western Europe.

Infections from Microsporum species are mainly in South America, Southern and Central Europe, Africa and the Middle East.

The increasing prevalence of dermatophytes resulting in Tinea capitis has been causing epidemics throughout Europe and America.

The disease is infectious.

Can be transmitted by humans, animals, or objects that harbor the fungus.

Common symptoms include severe itching of the scalp, dandruff, and bald patches where the fungus has rooted itself in the skin.

It often presents identically to dandruff or seborrheic dermatitis.

Highest incidence is in boys of school age.

There are three types:microsporosis, trichophytosis, and favus.

The types are based on the causative microorganism, and the nature of the symptoms

In microsporosis, the lesion is a small red papule around a hair shaft that later becomes scaly; eventually the hairs break off 1–3 mm above the scalp.

This disease used to be caused primarily by Microsporum audouinii

In Europe, M. canis is more frequently the causative fungus.

The source of this fungus is typically sick cats and kittens.

It may be spread through person to person contact, or by sharing contaminated brushes and combs.

In the United States, Trichophytosis is usually caused by Trichophyton tonsurans

T. violaceum is more common in Eastern Europe, Africa, and India.

Fungus causes dry, non-inflammatory patches that tend to be angular in shape.

When the hairs break off at the opening of the follicle, black dots remain.

Favus is caused by T. schoenleinii, and is endemic in South Africa and the Middle East

Favus is characterized by yellowish, circular, cup-shaped crusts grouped in patches, each about the size of a pea, with a hair projecting in the center.

As lesions increase in size and become crusted over, the lesion can only be seen around the edge of the scab.

May be difficult to distinguish from other scaling skin disease, such as psoriasis and seborrhoeic dermatitis.

Diagnosis by positive microscopic examination and microbial culture of epilated hairs.

ODiagnosis often is made solely on the basis of history and physical examination, findings of KOH preparations can be used to confirm the diagnosis, with the most common organism being Trichophyton tonsurans and Microsporium canis.

Wood’s lamp examination will reveal bright green to yellow-green fluorescence of hairs infected by M. canis, M. audouinii, M. rivalieri, and M. ferrugineum and a dull green or blue-white color of hairs infected by T. schoenleinii.

With M. canis infection trichoscopy shows characteristic small comma hairs.

Scalp biopsy shows fungi sparsely distributed in the stratum corneum and hyphae extending down the hair follicle.

The treatment of choice is griseofulvin, a secondary oral metabolite of the fungus Penicillium griseofulvin.

This compound is fungistatic works by affecting the microtubular system of fungi, interfering with the mitotic spindle and cytoplasmic microtubules.

While Griseofulvin is the standard of care, topical therapy can be used as an adjunct to prevent the shading and spread of spores.

Sporicidal shampoos containing selenium sulfide or ketocanazole can be used.

Oral and intra-lesional corticosteroids plus oral antifungal agents have shown only mild improvement in the discomfort caused by the lesions, with no improvement in cure rate.

The recommended pediatric dosage is 10 mg/kg/day for 6–8 weeks.

Other fungal skin infections that may be treated with topical therapies like creams applied directly to the afflicted area.

Griseofulvin must be taken orally to be effective, so that the drug can penetrate the hair shaft where the fungus lives.

Effective therapy rate of griseofulvin is in the range of 88–100%.

Other oral antifungal treatments for tinea capitis include terbinafine, itraconazole, fluconazole, and terbinafine hydrochloride.

From the site of inoculation of the fungus it grows down into stratum corneum, where it invades keratin.

Because dermatophytes produce keratinase, enabling them to use keratin as a nutrient source the infected hairs become brittle, and after three weeks broken hairs occur.

There are three types of infection exists:

Ectothrix: Characterized by the growth of fungal spores on the exterior of the hair shaft.

Infected hairs usually fluoresce greenish-yellow under a Wood lamp.

Ectothrix infections include: Microsporum canis, Microsporum gypseum, Trichophyton equinum, and Trichophyton verrucosum.

Endothrix: characterized by arthroconidia restricted to the hair shaft, and restricted to anthropophilic bacteria.

In endothrix infections the cuticle of the hair remains intact and does not have florescence.

Associated with Trichophyton tonsurans and Trichophyton violaceum, which are anthropophilic.

Favus: Causes crusting on the surface of the skin, combined with hair loss.

Favus infections are Associated with Trichophyton schoenleini.

Tinea capitis a contagious disease that is endemic in many countries.

Affects primarily pre-pubertal children between 6 and 10 years.

More common in males.

Rare for the disease to persist past age sixteen.

Spread occurs through direct contact with infected individuals and large outbreaks occur in schools and other places where children are in close quarters.

Indirect spread through contamination with infected fomites may also be a factor in the spread of infection.

Occurs in 3-8% of the pediatric population.

Up to one-third of households with contact with an infected person may harbor the disease without showing any symptoms.

The fungal species responsible vary according to the geographical region, and may also change over time.

A dermatophyte infection of the hair follicle and dermis that often presents in otherwise healthy and immunocompetent children.

Tinea kerion is an inflammatory response to a tinea capitis infection producing an elevated, boggy granulomatous mass often studded by pustules.

Tinea kerion isymptoms include pruritus, fever, local lymphadenopathy, and alopecia.