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Tinea Capitis

This is a fungal infection of the skin that affects the scalp, eyebrows and eyelashes. It can also attack the shafts and follicles of the hair and is a form of dermatophytosis. It is also known as tinea tonsurans and ringworm of the scalp. The frequency of tinea capitis is on the increase all over the world.

There are several distinct clinical entities for this disease which are based on the body structure and causes involved. The following are some of the clinical make up of these conditions:

• Tinea capitis
• Tinea favosa
• Tinea corporis
• Tinea imbricate
• Tinea cruris
• Tinea unguium
• Tinea pedis
• Tinea barbae

Tinea capitis varies in its visual effects from that of a scaly un-inflamed lesion that looks like seborrheic dermatitis to an inflamed scalp that has scaly and red lesions. Severe hair loss may also be involved that progresses to a much more serious inflammation called kerion. There is a potential to cause scarring and permanent hair loss with this condition.

The term “tinea” was originally used to indicate the eggs of insects that eat clothing and books, but it has been revised to mean a parasite infestation of the skin. The term described disease of the scalp and hair by the middle of the sixteenth century. Tinea and any skin disease that took on a ring-like form was referred to as ringworm. In the 1830s the causes of the various tinea infections on the beard and scalp were first identified and it was shown that several types of fungi cause the tinea capitis infection about fifty years later. It was discovered in 1904 that griseofulvin effectively treated the infection.

Pathophysiology

Tinea capitis is a very common dermophyte infection throughout the world that affects children. It is believed the presence of Pityrosporum orbiculare that exist in the periods prior to puberty causes the predisposition toward children. Another contributing factor is thought to be the fungi static properties of fatty acids.

The most common infectious disease agents known to invade humans is dermatophytes. Once these begin to grow they continue downward into the hair and invade the newly formed keratin. The fungi then extend up at the rate of hair growth and within twelve to fourteen days they become visible above the surface of the skin. By the third week the infected hairs become brittle and evidence of broken hairs can be seen. For approximately eight to ten weeks the infection continues long enough to spread farther and involve other hairs. The infected area is approximately 3.5 to 7.0 cm in diameter by this time.

Frequency

Since the disease is no longer registered with public health agencies the true incident is unknown even though it is widespread. However, it is believed that the greatest number occurs in school-aged black males. In 92.5 percent of children under the age of ten tinea capitis is the cause of dermatophytoses. In adults it is rare although it can occasionally be found in the elderly. In some of the urban areas of the Americas it is quite frequent. In ares of African and India it is also quite common. In Southeast Asia the rate of infection has actually declined from fourteen to 1.2 percent in the last fifty years. In northern Europe the disease occurs sporadically.

Sex/Age

Based on the type of fungus that is involved in the infection the frequency of tinea capitis varies by sex. In pre-puberty some fungal organisms affect as many as five times more boys than girls, but the after the onset of puberty the reverse seems to be true, possibly due to hormonal changes or because more children being exposed to infected women in those adolescent years. Girls are affected at a higher rate than boys with other fungal organisms so it depends entirely on the type of fungal organism that invades the scalp whether more boys or girls are affected.

Children younger than ten years are mostly affected by tinea capitis, though other age groups can occasionally be affected. Those between three and seven years are where the most incidences occur.

History

A reddened papule around a hair shaft on the scalp, eyebrows or eyelashes is the first sign of the infection. The papule appears paler and takes on a scaly appearance after a few days while the hair becomes discolored, brittle and lack luster. Also the hair will break off just above the skin surface of the scalp. Numerous papules will form within the typical ring formation as the lesion spreads. The ring-formed lesions may also combined along with other areas that have been infected already. In infected areas of the scalp hair loss is quite common.

Medical Care

For tinea capitis, topical treatments are usually ineffective. Ringworm of the head has been most effectively treated by griseofulvin. In the early stages of treatment to prevent the spread of the disease selenium sulfide shampoo has been found to be effective such as Selsum Blue.

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