Tinea capitis is a fungal infection of the scalp hairs. Tinea capitis is also known as ringworm and herpes tonsurans infection. It is caused primarily by the dermatophyte species Microsporum and Trichophyton. The fungi can penetrate the hair follicle outer root sheath and ultimately may invade the hair shaft. Clinically, tinea capitis divides into inflammatory and non-inflammatory types. The non-inflammatory type usually will not be complicated by scarring alopecia. The inflammatory type may result in a kerion (painful nodules with pus) as well as scarring alopecia. Tinea capitis occurs primarily in children between 3 and 14 years of age but, it might affect any age group. It may also involve the eyelashes and eyebrows.
Tinea capitis is caused by the dermatophyte species which have the capabilities to infect keratin and keratinized tissue including the hair. Dermatophytes include several genera like Trichophyton, Microsporum, and Epidermophyton. Some common organisms include Trichophyton soudanense, Trichophyton tonsurans, Trichophyton verrucousum, Trichophyton rubrum, and Microsporum canis. Transmission of the infection takes place through direct contact with organisms from:
Tinea Capitis is a common dermatological disease. Tinea capitis is seen almost all over the world. It is most common in hot, humid climates such as Africa, Southeast Asia, and Central America. Sexual predilection varies depending on the causative dermatophytes, e.g., Trichophyton infections will affect both sexes equally during the childhood years. Microsporum canis affects boys more than girls. Tinea capitis affects children more than adults.
Immunosuppression may lead to impaired hair shaft growth and strength leading to easier colonization. Other associated diseases include:
It is worth mentioning that in HIV the risk is not increasing due to competitive colonization with Malassezia.
Hair will typically get infected in one of three principal ways:
1) Endothrix: where the fungi affect the hair shaft - an example of this type: Trichophyton tonsurans
2) Ectothrix: where the fungi affect the outer sheath root - an example of this type: Microsporum canis
3) Favus: where there is an inflammatory reaction, crusting or scutula, and hair loss - an example of this type: Trichophyton schoenleinii,
Tinea capitis shows the following histological findings:
Periodic acid-Schiff stain is a special stain that will help in identifying the fungi. Also neutrophilic infiltrates might be seen in the papillary dermis.
Tinea capitis usually affects children. Therefore, it is essential to inquire about any colleagues and friends from the school that have the same condition; this might give a clue about the mode of transmission. The infection usually starts as red papules that will increase in size with the time. As the infection spreads, it might involve the whole scalp. The skin of the infected area of the scalp may be normal close to the center of the round patch, but will probably appear irritated, red, or inflamed near the edges. Symptoms of tinea capitis include redness, itching, scale formation, and alopecia.
The symptomatic presentation of ringworm infection of the scalp is quite different depending upon the causative organism. Commonly, the infection may look like severe dandruff that appears on various places on the scalp. Some infections cause patches of hair loss. The inflammatory type (kerion) is associated with pus discharge and might lead to permanent hair loss.
There are three distinct clinical presentations which include:
Black dot tinea capitis, which is the classical presentation: in this type, there is an infection with a fracture of the hair.
Kerion is another presentation which involves inflammation and may progress to scarring alopecia.
Favus, which is the boggy inflammatory type and typically presents with deep-seated oozing nodules, abscesses, crusting or scutula.
One may consider a fungal culture swab, biopsy, or scraping from the scalp in patients with tinea capitis. A fungal culture may confirm the causative fungus. The scraping can be done and placed on a glass slide. A few drops of KOH 20% solution is added, and the slide is examined under a microscope to look for hyphae and spores.
Woods light is a modality to check for fluorescence of the infected areas. With a woods light, infected hairs by M. canis, M. audouinii, M. rivalieri, and M. ferrugineum will give a green to a yellow-green color. Infection with T. schoenleinii may show a blue color.
Tinea capitis can is treatable with systemic antifungal medications. Often the drug of choice is griseofulvin.
Azole antifungal medications like itraconazole and fluconazole are also alternative treatment options. Specific presentations like kerion need anti-inflammatory treatments like systemic steroids for a short period to help to reduce the inflammatory response and also consequently lower the risk of permanent alopecia. This steroid therapy is in addition to the oral antifungal treatment. Allylamines are a great option orally, like terbinafine.
Anti-fungal shampoos can be part of the treatment plan and often help in preventing spread, but this is not the mainstay of treatment and will usually not cure tinea capitis. Creams may also help in preventing the spread of tinea capitis but typically will not cure this condition.
Most oral antifungal treatment may increase liver enzymes, therefore, consider checking liver enzymes before initiating, during, and after therapy.
Tinea capitis usually has a good prognosis when treated early and appropriately.
The easiest method of preventing tinea capitis is avoiding situations where the patient can acquire it from another person or animal. Health care professionals should coordinate as a team across disciplines in identifying the condition, treating, and tracking down the source of contamination.
Children should be instructed not to share caps, hair brushes, and combs. Pillows, as well as bed linens, should be washed thoroughly. The fungi responsible for tinea capitis can live for long periods. Hair equipment needs to be cleaned and also disinfected or replaced altogether.
Working as a team and eliminating sources of contamination helps reduce the morbidity of this condition.
|||Dei-Cas I,Carrizo D,Giri M,Boyne G,Domínguez N,Novello V,Acuña K,Dei-Cas P, Infectious skin disorders encountered in a pediatric emergency department of a tertiary care hospital in Argentina: a descriptive study. International journal of dermatology. 2018 Sep 24 [PubMed PMID: 30246865]|
|||Souissi A,Ben Lagha I,Toukabri N,Mama M,Mokni M, Morse code-like hairs in tinea capitis disappear after successful treatment. International journal of dermatology. 2018 Sep 28 [PubMed PMID: 30264392]|
|||Coxe, History of a Case of Tinea Capitis Cured by Vaccination. The Medical and physical journal. 1807 Oct [PubMed PMID: 30492178]|
|||Barlow J, Observations on the Mode of Curing the Tinea Capitis. The Medical and physical journal. 1805 Dec [PubMed PMID: 30491951]|
|||Al-Refu K, Clinical Significance of Trichoscopy in Common Causes of Hair Loss in Children: Analysis of 134 Cases. International journal of trichology. 2018 Jul-Aug [PubMed PMID: 30386074]|
|||Chodkiewicz HM,Ranario JS,Jahan-Tigh R,MacFarlane DF,Petronic-Rosic V, Tinea Capitis Masquerading as Basal Cell Carcinoma. Skinmed. 2018 [PubMed PMID: 30207532]|