Tinea Capitis (Scalp Ringworm)

Tinea capitis, commonly called scalp ringworm, is a contagious fungal infection of the scalp and hair caused by fungi known as dermatophytes. Despite the name ringworm, no worm is involved. The condition occurs most commonly in children but can affect people of any age.

Tinea capitis can cause scaling, itching, broken hairs and one or more areas of visible hair loss. Some infected hairs break close to the scalp, producing characteristic black dots. More inflammatory cases can cause tenderness, pustules, crusting or a swollen, boggy inflammatory mass known as a kerion.

A chronic form of tinea capitis known as favus can produce thick yellow crusts around affected hairs and, when severe or longstanding, may result in permanent scarring hair loss.

Species of Trichophyton and Microsporum are among the major fungal causes of tinea capitis worldwide. The organisms responsible can vary by geographic region, population and whether transmission occurs primarily between people or from animals.

Tinea capitis can spread through direct contact with an infected person or animal and through contaminated objects such as combs, brushes, hats, bedding and towels. Because family members or other close contacts can sometimes carry the organism without obvious symptoms, controlling transmission may also be part of treatment.

Diagnosis may involve examination of the scalp and hair, trichoscopy, microscopic examination, fungal culture or other laboratory testing. Identifying the organism can sometimes help guide the choice of treatment.

Because the fungus infects the hair shaft and follicle, tinea capitis generally requires prescription oral antifungal medication. Depending on the organism, age and individual patient, medications such as terbinafine, griseofulvin, itraconazole or fluconazole may be used. Antifungal shampoos can help reduce fungal shedding and transmission but generally are not sufficient as the only treatment.

Early recognition is particularly important when marked inflammation, kerion or favus is present because significant inflammatory damage can permanently injure hair follicles.

Folliculitis

Folliculitis means inflammation of one or more hair follicles. It can occur anywhere hair grows and may appear as small red or pus filled bumps centered around individual follicles. Symptoms can include itching, burning, tenderness or pain.

Many cases are associated with microorganisms. Bacterial folliculitis is commonly caused by Staphylococcus aureus. Pseudomonas bacteria can produce so called hot tub folliculitis after exposure to inadequately maintained pools or hot tubs. Yeasts such as Malassezia and, less commonly, other fungi, viruses or mites can also be associated with follicular inflammation.

Not every case of folliculitis is infectious. Shaving, friction, occlusion, certain medications and inflammatory skin disorders can produce folliculitis or conditions that closely resemble it. Scalp folliculitis therefore should not automatically be treated as a bacterial infection without considering the underlying cause.

Most superficial folliculitis does not cause permanent hair loss. Persistent, deep or severe inflammation involving the scalp can occasionally damage follicles, and some chronic follicular disorders can produce permanent scarring alopecia.

Treatment depends on the cause and severity. Mild cases may resolve with appropriate scalp or skin care, while persistent, recurrent, painful or widespread folliculitis should be medically evaluated. Depending on the diagnosis, treatment may involve antibacterial, antifungal, anti inflammatory or other prescription therapies.

Piedra

Piedra is a superficial fungal infection of the hair shaft characterized by small nodules attached to individual hairs. The name comes from the Spanish word for stone. Two principal forms are recognized: black piedra and white piedra.

Black piedra is caused by the fungus Piedraia hortae and occurs most commonly in tropical climates. It produces firm, dark brown or black nodules that adhere tightly to the hair shaft.

White piedra is most commonly associated with species of Trichosporon and produces softer white, tan or light brown nodules. Depending on the organism and circumstances, piedra can involve scalp, facial or body hair.

Because the infection primarily involves the hair shaft rather than the follicle, piedra usually causes little inflammation or discomfort. Affected hairs can become weakened and break, however, creating the appearance of thinning or hair loss when infection is extensive.

Diagnosis can involve examination of affected hairs, trichoscopy, microscopy and fungal culture. Piedra may sometimes be confused with head lice, hair casts or abnormalities of the hair shaft.

Treatment depends on the type and severity of infection and may include cutting or removing affected hairs together with topical antifungal therapy. Oral antifungal medication may be considered for persistent or extensive cases.

Demodex Folliculorum

Demodex folliculorum is a microscopic mite that normally lives within or near human hair follicles. Demodex mites are extremely common in adults and, in most people, are part of the normal skin environment without causing symptoms or hair loss.

Claims that ordinary Demodex colonization is a major cause of common hair loss or that eliminating these mites will restore hair in people with androgenetic alopecia are not supported by established evidence.

Under unusual circumstances, however, excessive numbers of Demodex mites have been associated with inflammatory skin and follicular disorders. Rare cases of Demodex associated scalp folliculitis have been reported with redness, scaling, pustules and hair loss. This is very different from simply finding Demodex mites on otherwise normal skin.

Treatment directed specifically at Demodex should therefore be based on evidence of a clinically significant condition rather than the presence of mites alone.