Tinea Capitis and Trichoscopy - An Overview

Introduction:

Tinea capitis is the most common dermatological infection affecting children's scalp, especially those with low socioeconomic strata. It causes patches of hair loss, itching, red and scaly skin. The prevalence of tinea capitis varies from seven percent to 48 percent. Trichoscopy aids in early diagnosis of tinea capitis and prompt treatment to avoid contamination and complications. It is a diagnostic tool that can get a close-up look at the scalp and hair to diagnose conditions like tinea capitis. Understanding tinea capitis and trichoscopy helps in early diagnosis, prompt treatment, and prevent complications. The article discusses tinea capitis, trichoscopy, tinea capitis causes, their symptoms, diagnosis, and treatment.

What Is Tinea Capitis?

Tinea capitis is a fungal infection affecting the hair and skin. It is also called scalp ringworm or ringworm of the hair. Trichophyton and Microsporum species mainly cause the infection. Tinea capitis is found in various parts of the world. However, the species causing tinea capitis varies geographically. Trichophyton species predominate in the United States, Central America, and Europe. Microsporum species predominate in South America, Africa, and Southern and Central Europe. It mainly affects children, and the average age at which it affects them is between three and seven years. Immunocompromised adults are also affected.

What Are the Causes and Risk Factors of Tinea Capitis?

Dermatophytic fungi cause tinea capitis. This type of fungus invades the keratinized tissue present in nails and hair. Dermatophytic fungi thrive in warm and moist environments and can infect the hair follicles and scalp. Trichophyton and Microsporum are the main species that cause tinea capitis. Trichophyton tonsurans (anthropophilic dermatophyte), Trichophyton violaceum (anthropophilic fungi), and Microsporum canis are the common species causing the condition. Tinea capitis can be spread through direct and indirect contact.

• Direct Contact: Close contact with infected people or pets, such as cats and dogs, can carry fungi and infect a healthy person.

• Indirect Contact: Fungi can survive on surfaces such as floors and furniture, and healthy people can contract the infection from contaminated surfaces. In addition, sharing towels, combs, hats, pillows, and brushes with an infected person can cause the infection.

Risk Factors:

• The infection mainly affects children, especially in schools and daycare centers.

• Poor hygiene practices increase the risk of spread of an infection.

• Individuals with weakened immune systems are more likely to have infections.

How Does Tinea Capitis Infection Occur?

After the invasion of dermatophyte fungi into the scalp, the fungus goes downwards into the hair follicle and invades the hair shaft. The three ways of penetration of the fungus into the hair shaft are as follows:

• Ectothrix Infection: The growth of the fungus is within the hair follicle and covers the hair surface. Fungal spores are more pronounced on the exterior surface of the hair shaft. The infected hairs fluoresce greenish-yellow color under a wood lamp (a diagnostic tool). The ectothrix infections include Microsporum canis, Microsporum gypseum, Trichophyton verrucosum, and Trichophyton equinum.

• Endothrix Infection: This infection is similar to endothrix infection, but the fungus is restricted to the hair shaft and grows in it. The cuticle is not destroyed, and there is no fluorescence. Endothrix infection is associated with Trichophyton tonsurans and Trichophyton violaceum.

• Favus Infection: It is a chronic fungal infection caused by Trichophyton schoenleinii. There is a presence of hyphae clusters at the hair base. Clinically, there is a yellow crusting on the skin surface, with hair loss.

What Are the Signs and Symptoms of Tinea Capitis?

The signs and symptoms of tinea capitis are based on the fungus species. Common symptoms in all fungus species include partial hair loss with inflammation. The signs and symptoms of tinea capitis are classified into inflammatory and non-inflammatory variants and that are described below:

Non-Inflammatory Variants: The associated symptoms are as follows:

• Grey Patch: Grey appearance of scalp scaling and alopecia (immune system attacks hair follicles and causes hair loss) patches due to the coating of the fungal spores on the affected hairs. There will be redness and inflammation of the mucus membrane.

• Black Dot: Scalp scaling and alopecia patches are covered with a large number of black dots, which are broken hair shafts.

• Hair Loss: Hair may break off and leave small bald patches.

Inflammatory Variants: The inflammatory variants are as follows:

• Diffuse Pustule: Small pus-filled bumps, pustules, or sores on the scalp with patchy alopecia appear. There is a chance of secondary fungal and bacterial infection.

• Keroin: It is a chronic inflammatory reaction in which the affected person's immune response to the fungus is delayed, forming a large, swollen mass called keroin. If left untreated, the affected person may experience pain accompanied by pus, which may lead to permanent scarring and hair loss.

• Favus: Presence of yellow crusting and cup-shaped lesions on the hair's base. The hyphae and keratin debris coalesce and form a large mass.

• Enlarged Lymph Nodes: The lymph nodes in the neck are enlarged and tender.

How Does Trichoscopy Diagnose Tinea Capitis?

Trichoscopy is a non-invasive diagnostic technique that uses a dermatoscope to magnify and illuminate the hair and scalp. However, some dermatologists use dermoscopy to diagnose pigmented skin lesions. Dermoscopy helps recognize pigmented skin lesions and inflammatory dermatoses. The dermatoscope in the trichoscopy provides a clear and magnified view of the scalp and hair. It helps dermatologists to observe things that cannot be visible to the naked eye.

Trichoscopy Procedure: The dermatoscope is placed on the scalp, and images are captured and viewed through the lens. The dermatologist examines the various regions of the scalp and checks for signs of tinea capitis.

Findings: The characteristics findings are as follows:

• In infected areas, short, broken hairs or comma hairs are seen. These hairs are broken at different lengths.

• The broken hair shafts on the exterior surface of the scalp appear as black dots, indicating that the hairs are broken due to the fungal infection.

• Fine gray scales are visible with trichoscopy.

• With tinea capitis, twisted or corkscrew hairs are seen in African people.

• Dilated follicular openings with keratotic material.

• Small pus-filled pustules.

How Is Tinea Capitis Managed?

The treatment strategies for tinea capitis are as follows:

• The dermatologist may prescribe antifungal medications, such as Griseofulvin, Terbinafine, Fluconazole, and Itraconazole. This will help reduce the spread of the fungus.

• The topical treatment includes medicated shampoos containing Ketoconazole.

• People should avoid sharing towels, combs, hats, and pillows.

• People should regularly clean and disinfect the contaminated surfaces.

• Keep the scalp clean and dry.

Conclusion:

Tinea capitis is a fungal infection that affects children's scalps and hair. The affected person may experience pain, scaly scalp, hair loss, and pus-filled pustules. Trichoscopy is the diagnostic procedure for tinea capitis. Oral and topical antifungal drugs can manage the condition. People should maintain scalp hygiene, avoid sharing personal things, and regularly clean contaminated surfaces. If an individual is experiencing any symptoms, they should contact a dermatologist for early treatment and prevent complications.