Tinea capitis: affects the head (usually found in children)
Tinea capitis is also called ringworm of the scalp/ hair, tinea tonsurans or herpes tonsurans. It is a condition where the dermatophytes affect the hair shaft and scalp. It is most often seen in young people (children between 3 and 14 years of age), is much more common in Afro-American individuals that Caucasians and affects more boys than girls. Although this is an infection that mainly occurs in children and usually does not persist past age sixteen, it may be seen in adults with AIDS. Tinea capitis is very rare in children younger that one year, but still possible. Usually these infants are immunologically normal, but an underlying disorder must be excluded.
Usually the lesions persist from weeks to months.
The presentation of the tinea capitis: can vary greatly- from scaling that does not appear inflamed to scaling with broken hair and even severe inflammation with painful nodules with pus (called kerion). The latter can result in alopecia (loss of hair) due to scarring. Itching might be present or not.
There are more than eight species of dermatophytes that cause tinea capitis. It is difficult to determine the species that predominates because the incidence varies from country to country, form continent to continent. It may even change in time because of people immigrating abroad.
The transmission of the infection occurs from person to person, from animals to people, with contaminated objects (combs, towels, pillows, theater seats and so on) or by contact with an asymptomatic carrier (a person who does not appear to have an active inflammation). The transmission is more common were there is poor hygiene, overcrowding and a low socio- economic status. There are also some risk factors that predispose for a more serious curse of the infection: malnutrition of the patient, chronic disease or debilitation.
The clinical appearance depends on the type of the infection and the host immune response. Generally speaking, it usually results in scaling, breakage and loss of hair and a inflammatory response that extends to different degrees. When describing Tinea capitis it is useful to recognize these commonly seen forms:
- Gray patch tinea capitis: it occurs in epidemic and endemic forms. The epidemic form has almost disappeared from North America, but the endemic form contracted from domestic pets still persists. The infection begins with a red colored patch on the scalp that scales and grows centrifugally for some weeks of even months. After that the growth stops and the patch persists for a long time. The lesion can be solitary or multiple, in the infected area the hair breaks about a millimeter or two above the skin. In some patients the appearance of the lesion changes, becomes elevated, painful with nodules (kerion). This is the result of the body answering to the fungal invasion which can, in some cases, become complicated by a bacterial infection. Sometimes even the lymph nodes may become enlarged and painful.
- Black dot tinea capitis: is the most common form of Tinea capitis in the United states. Usually seen in children, it can occur in adults – especially older people. It spreads by direct contact with the infected, by contact with the infected items or by contact with a asymptomatic individual. Afro- American children appear to be more susceptible. Usually, the infection begins as an asymptomatic, reddish scaling patch on the scalp which enlarges slowly. Because it may not cause a lot symptoms, it is easily overlooked until te hair starts to break off. When the hair falls off, the opening left behind appears as a black dot – hence the name black dot tinea capitis. Sometimes there is so much inflammation that the condition can be easily mistaken for a bacterial infection of the skin. If the condition remains untreated, it can progress to permanent scarring and hair loss.
- Favus: this form of disease persist in certain parts of the world (China, Nigeria and Iran), elsewhere its occurrence has decreased. Usually, the disease starts with redness around the hair follicles that evolves forming concave, cup-like shaped yellow crusts (called scutula). These crusts are composed of dead inflammatory cells, fungi, dried scalp secretions and skin cells. If the condition is left untreated the crusts confluent and the hair under them falls out. It appears that prolonged contact is needed for the spread of the infection.
Diagnosis of Tinea capitis
KOH examination (treating the scrapings of the sking with potassium hydroxide) may be enough for diagnosis. The Wood lamp (UV lamp for detecting certain fungi species) can be used but not all of the species will glow under it. Sometimes dermoscopy findings (a noninvasive diagnostic technique that enables an experienced clinician to perform direct microscopic examination of skin lesions) might be of help in determining a ringworm infection of the scalp. Specific findings include curved and broken (comma) hairs and corkscrew-shaped hairs.
Treatment of Tinea capitis
because the pathogens in this disease are out of reach for topical medications, oral antifungals usually have to be used. The systemic treatment usually consists of griseofulvin, terbinafine, itraconasole or fluconasole that must be taken (on average) a couple of weeks. The treated patient must be scheduled for follow-up visits with the doctor and the treatment prolonged if there are signs of active disease at the end of the planed course.
It is important for the household members of the infected individual to be scanned for a possible infection and if so, treated with appropriate medications.
Children can benefit from use of shampoo preparations of selenium sulfide, zinc pyrithione, povidone iodine or ketoconazole as additional therapy 2-4 times weekly for 2-4 weeks. The same treatment is also advised for the patient’s household members to prevent reinfections.
Although trials showed no difference in cure rates when using antifungal agents plus anti inflammatory drugs in contrast to using antifungals alone when treating kerion, the anti inflammatory glucocorticoids can still be used to relive discomfort.
Course of the disease
The prognosis of Tinea capitis is somehow difficult to assess because of many factors that have to be included and a very variable presentation. It is mandatory for the patient to stick with the prescribed treatment regimens and to keep the environment and himself clean. If left untreated, kerion and favus can result in scarring and loss of hair. If the patient is treated with oral antifungal agents regrowth of hair is to be expected. Favus is a condition that can persist into adulthood.