What Is Tinea Capitis

Introduction

Tinea capitis commonly known as scalp ringworm, is a contagious fungal infection that affects the scalp and hair shafts. It presents with characteristic symptoms such as patches of itchy skin and scaly and bald skin, often forming a circular pattern resembling ringworm. This infection is caused by dermatophytes, fungi that require keratin for growth, and primarily affects children but can occur in individuals of all ages. 

Recognising its means of transmission, symptoms, diagnosis, risk factors, and treatment highlights the vital importance of comprehending and incorporating preventive strategies in daily life. 

What is tinea capitis?

Tinea capitis is a fungal infection that affects the scalp and hair shafts, causing small patches of itchy, scaly, bald skin. Tinea capitis is also known as scalp ringworm because of its circular appearance or herpes tonsurans infection.¹ It is caused primarily by Microsporum canis and Trichophyton tonsurans, both of which fall into the classification of dermatophytes.

Dermatophytes are fungal organisms that require keratin for growth. These can cause infections to the skin, hair and nails. These microscopic fungi take advantage of various transmission methods to spread the infection. The leading cause of tinea capitis in the United Kingdom is Trichophyton tonsurans.²

From a clinical perspective, tinea capitis can be categorised into two types: 

• Inflammatory
• Non-inflammatory. 

The non-inflammatory type generally doesn’t lead to scarring hair loss. On the other hand, the inflammatory type can give rise to kerion formation, characterised by painful large pus-filled sores which may also contribute to scarring hair loss.³ It occurs primarily in toddlers and school-age children (between 3 and 14 years of age), but it can affect all age groups. It can also affect the eyelashes and eyebrows, as well as the scalp. 

Symptoms

Generally, the infection starts as red papules that gradually increase in time. As the infection continues to spread, it might involve the whole scalp. The symptoms of the infected area may present as followed:³

• Redness 
• Itchiness
• Dry, scaly rashes
• Scale formation that resembles dandruff
• Patches of hair loss (alopecia)

Tinea capitis can cause patches called kerions. These are painful pus-filled sores on the scalp. This may eventually cause inflammation on the scalp, leading to hair loss. Round, bald patches with black dots where the hair has broken off is a classic presentation of tinea capitis - those with blond hair will present with blond dots. 

In addition to the symptoms seen on the scalp, some may have swollen glands in the neck and back of the head. As well as the spread of the infection to the eyebrows and eyelashes.

Diagnosis

Tinea capitis infection is diagnosed by a combination of physical examination and laboratory testing. For those with symptoms, a doctor will look at your scalp and hair. If they think that the cause of the symptoms may be due to tinea capitis infection, they will take skin and hair samples from the scalp and send them off to be tested in a laboratory.⁴  These samples are then examined under a microscope and cultured to find out whether a fungal infection is the underlying cause. Due to the slow, gradual growth of the fungus, culture results can take up to 6 weeks to be produced. 

Risk factors

Tinea capitis affects both sexes equally. It is primarily seen in toddlers and school-age years. However, infections can be seen across all age groups. Microsporum canis is more common in girls, whereas Trichophyton tonsurans is more common in boys. The fungal infection is seen almost all over the world but is most commonly found in hot, humid climates.⁴ This coincides with fungi's natural tendency to grow in areas with high moisture and warm temperatures.⁵

Tinea capitis is contagious, resulting in these microscopic fungi taking advantage of various transmission methods to spread the infection. Direct contact with an infected individual allows fungi to move from one host to another. Through this direct contact, large outbreaks have been known to occur in schools and other places where children are in close contact with one another. Additionally, indirect spread can be caused by shared contaminated objects (fomites) such as combs, hats and pillows, which may also be a factor in the spread of the infection.  

Although not commonly seen in adults, there are factors that can lead to increased risk to tinea capitis, such as postmenopausal women6 and immunosuppression. Immunosuppression may lead to impaired hair shaft growth and strength, leading to easier colonisation of the fungal infection. Other associated diseases include:⁴

• Diabetes
• Prolonged steroid use
• Cancer
• Immunosuppressant medication
• Anaemia

Treatment

Tinea capitis needs to be treated with a combination of an antifungal medication taken as a tablet and an antifungal cream or shampoo to reduce the risk of transmission to others.

According to the National Institute for Health and Care Excellence (NICE), the oral antifungal treatments used are griseofulvin and terbinafine. Treatment regimes can depend on where you live and the specific fungus causing infection. 

• If the individual lives in an urban area (most likely Trichophyton tonsurans), terbinafine would be prescribed for 4 weeks.
• If the individual lives in a rural area (most likely Microsporum canis), griseofulvin would be prescribed for 4-8 weeks.
• The use of itraconazole for 4 weeks can be considered if griseofulvin is not tolerated.

Side effects from these treatments can include: 

• Diarrhoea 
• Nausea 
• Vomiting 
• Rash 
• Headaches 

When taking griseofulvin, certain precautions should be made if you are taking any oral contraceptive to prevent pregnancy. Effective contraception is required for women for at least 1 month after use. The effectiveness of oral contraceptives can be compromised; therefore, additional contraceptives are recommended, such as barrier methods (female/male condoms). Men treated with griseofulvin should also use contraception during and for at least 6 months after treatment, as it can damage the sperm, which potentially leads to abnormalities in the foetus. 

There are a range of topical antifungal treatments available. Options include shampoos such as ketoconazole which is to be used twice weekly for 2-4 weeks, or an imidazole cream (e.g. clotrimazole) to be used daily for a week.

Complications

When left untreated, there are a range of complications that can arise:⁴

• Scarring alopecia (hair loss);
• Psychological/ emotional impact;
• Dermatophyte (id) reaction: a secondary rash which may occur with tinea capitis and particularly may start after the initiation of antifungal treatment.
• Erythema nodosum - swollen fat under the skin, causing red, painful patches and bumps. 
• Pigmentation changes 
• Secondary bacterial infection 

Prevention

Tinea capitis is both common and contagious, which can complicate prevention efforts. Nonetheless, there are strategies to reduce the risk of its occurrence:

• Maintain hygiene: Regularly washing your hair and scalp. Make sure to keep your scalp dry and clean, as fungi thrive in warm environments.
• Avoid sharing personal items: Tinea capitis can spread through fomites such as combs, brushes and pillows. This should be avoided, especially in communal environments such as gyms and schools.
• Educate children: It is important to teach children the importance of personal hygiene and to avoid sharing personal items, especially as it is commonly thought in their age group. Therefore, this could significantly reduce the risk of spreading the infections in schools and other places where children gather together. 
• Regularly clean and disinfect: Clean and disinfect common areas, especially environments where people are close. In addition, wash bedding regularly as the fungi can transfer onto fabrics, infecting individuals when coming into contact.
• Avoid close contact: Limit close contact with individuals, including animals, who have visible symptoms, such as patches, of tinea capitis. This can help prevent direct transmission of the infection.

Summary

Tinea capitis is a form of fungal infection caused by the Microsporum canis and Trichophyton tonsurans species of fungi. Infection usually causes itchy, red and scaly rashes on the scalp, which lead to painful pus-filled sores and hair loss if left untreated. Infection can also spread to other areas of hair growth, like the eyebrows and eyelashes.

Infection is diagnosed by physical examination and laboratory-tested cultures and treated with both oral and topical antifungal medication. Care should be taken to prevent being infected with tinea capitis by avoiding contact with infected individuals, maintaining a high level of hygiene and cleanliness, and not sharing personal items that can spread infection. If left untreated, tinea capitis infection can cause considerable harm to the skin of the scalp, cause permanent hair loss, as leave you more susceptible to bacterial infections.