Scalp Ringworm

Itching, flaking, and scales attached to the hair may lead many people to assume that they simply have dandruff. However, if these symptoms persist and are accompanied by patchy hair loss, broken hairs, or scalp inflammation, they may indicate scalp ringworm, which requires a different form of treatment from ordinary dandruff.

Scalp ringworm can spread from one person to another. It may also be transmitted through infected animals or contaminated objects. Recognizing the symptoms and receiving an appropriate medical evaluation are therefore important, as shampoo or topical medication alone may not be sufficient to eliminate fungi that have entered the hair shafts and follicles.

What Is Scalp Ringworm?

Scalp ringworm, medically known as tinea capitis, is a fungal infection that affects the scalp, hair shafts, and hair follicles. It is caused by a group of fungi called dermatophytes, which can grow in areas containing keratin, such as the skin, hair, and nails.

Although the English term "ringworm" is commonly used, the condition is not caused by worms or parasites. The name comes from the ring-shaped appearance that fungal rashes may develop on some areas of the skin. On the scalp, however, the rash may not form a clearly defined ring. Instead, it may appear as areas of scaling, broken hairs, or patchy hair loss.

Scalp ringworm is most common in children, particularly school-age children, because they are more likely to have close physical contact and share personal items with others. Adults can also become infected, especially older adults, people with weakened immune systems, and those who have close contact with infected individuals or animals.

The severity of the condition varies. Some people may experience only mild flaking and itching that resemble dandruff, while others may develop significant inflammation, pustules, scalp swelling, or widespread hair loss.

Causes and Factors Associated With Scalp Ringworm

Scalp ringworm develops after exposure to dermatophyte fungi from people, animals, contaminated objects, or the environment. The fungi can enter the surface layers of the skin, hair shafts, and hair follicles, where they multiply and cause symptoms.

The main routes of infection include the following.

Direct Contact With an Infected Person

Direct contact with the scalp, hair, or skin of an infected person is a common route of transmission. The risk is higher among people living in the same household, children who play closely together, and individuals whose work involves regular contact with other people's hair.

Some infected individuals may have only mild symptoms or no obvious symptoms, but they may still carry fungi on the scalp and transmit the infection to others.

Sharing Personal Items

Fungi can remain on objects that come into contact with the scalp or hair, including combs, hairbrushes, hats, helmets, towels, pillowcases, bedding, hair clips, and hair-cutting equipment.

Sharing these items with an infected person, particularly when they have not been cleaned properly, may increase the risk of infection.

Contact With Infected Animals

Some pets, particularly cats and dogs, can carry the fungi that cause ringworm. Infected animals may develop patchy hair loss, flaky skin, scales, or redness. However, some animals can carry the infection without showing obvious symptoms.

If someone in the household develops scalp ringworm and a pet has unusual hair loss or skin changes, the animal should be examined by a veterinarian. Human medication should not be used on animals without professional advice.

Exposure to Fungi in the Environment

Some types of fungi can be found in soil. Infection from soil is less common than transmission from people, animals, or contaminated objects, but it may occur, particularly when the scalp has cuts, abrasions, or irritation.

Factors That May Increase the Risk

Hot and humid conditions, excessive sweating on the scalp, crowded living environments, and sharing personal items may make fungal transmission more likely.

Young children, older adults, people with weakened immune systems, those taking immunosuppressive medication, and individuals with certain underlying health conditions may have a higher risk of infection or more severe symptoms.

Symptoms of Scalp Ringworm

Symptoms of scalp ringworm vary depending on the type of fungus and the body's response to the infection. In some cases, the condition may resemble dandruff, seborrheic dermatitis, psoriasis, or another skin disorder.

Possible symptoms include:

• Flaking or scaling in patches on the scalp
• An itchy scalp
• Redness or a rash on the scalp
• Brittle hair that breaks easily
• Broken hairs of uneven lengths
• Circular or patchy hair loss
• Black dots on the scalp where hairs have broken near the roots
• Thick scales or crusts on the scalp
• Raised bumps, pustules, or sores that discharge fluid
• Swelling, redness, or tenderness of the scalp
• Enlarged lymph nodes in the neck or behind the ears

An important feature that may help distinguish scalp ringworm from ordinary dandruff is the presence of broken hairs, patchy hair loss, black dots around the hair follicles, or scalp inflammation. Dandruff commonly causes widespread flaking and itching but does not usually cause clearly defined areas of hair loss.

Some patients develop severe inflammation that forms a soft, swollen area known as a kerion. It may be red, painful, filled with pus, or discharge fluid. If severe inflammation continues for an extended period, scarring may develop around the hair follicles, increasing the risk that some hair may not grow back normally.

When to Seek Medical Attention Promptly

Most cases of scalp ringworm are not life-threatening emergencies. However, medical evaluation should be obtained promptly because treatment usually requires an oral antifungal medication, and the infection can spread to people who have close contact with the patient.

Seek medical attention promptly if any of the following symptoms occur:

• Severe swelling, redness, warmth, or tenderness of the scalp
• Swollen areas, pustules, open sores, or fluid discharge
• Rapid or widespread patchy hair loss
• Thick crusts covering the scalp
• Fever, fatigue, or general illness
• Painful or enlarged lymph nodes in the neck or behind the ears
• Symptoms in a child, particularly when accompanied by hair loss
• An underlying condition that weakens the immune system
• Current use of immunosuppressive medicines, corticosteroids, or chemotherapy
• Symptoms that do not improve, return repeatedly, or worsen during treatment

Anyone who suspects scalp ringworm should consult a doctor even if the symptoms are not severe. Shampoo or topical medication alone may not eliminate fungi that have entered the hair shafts.

How Is Scalp Ringworm Transmitted?

Scalp ringworm is contagious. The fungi can spread from person to person, from animals to people, and through contaminated objects.

Person-to-person transmission commonly occurs through direct contact with the scalp or hair of an infected person. Prolonged close contact, sleeping together, or playing closely may increase the risk of infection.

The infection can also spread through objects that have come into contact with the scalp, such as combs, hats, towels, pillowcases, bedding, and hair-cutting equipment. Sharing these items without proper cleaning may allow the fungi to spread to another person.

Infected animals can transmit the fungi to people through contact with their fur or skin. Some animals may carry the fungi without showing obvious symptoms. If an infection in a pet is suspected, the animal should be examined by a veterinarian to reduce the risk of repeated infection within the household.

In addition, scratching the infected area and then touching another part of the body may spread the fungi to the face, torso, arms, legs, or nails. Hands should therefore be washed after touching the scalp, and scratching or picking at the affected area should be avoided.

How Do Doctors Diagnose Scalp Ringworm?

A doctor will ask about the symptoms, how long they have been present, possible contact with infected people, the sharing of personal items, and exposure to pets. The scalp, hair, and other areas of the skin will then be examined.

In some cases, the doctor may collect skin scales or hairs from the affected area for microscopic examination or fungal culture. These tests can help confirm the infection and distinguish it from other conditions with similar symptoms.

A dermatoscope or a special type of light may also be used in some cases. The most appropriate diagnostic method will depend on the symptoms and the doctor's clinical judgment.

Treatment of Scalp Ringworm

Treatment depends on the patient's age and weight, the type of fungus, the severity of the infection, underlying health conditions, current medications, and the doctor's assessment.

Oral Antifungal Medication

Scalp ringworm usually requires treatment with an oral antifungal medication because the fungi can enter the hair shafts and follicles. Topical medication alone may therefore not reach the infection adequately.

Treatment may take approximately one to three months, depending on the medication used, the type of fungus, and the response to treatment. Patients should take the medication continuously as prescribed and should not stop treatment on their own, even if the symptoms have improved.

Antifungal medicines may require certain precautions and may interact with other medications. People with liver disease, those who take regular medication, pregnant or breastfeeding women, and anyone with a history of medication allergies should inform their doctor before starting treatment.

Antifungal Shampoo Used Alongside Treatment

A doctor may recommend using an antifungal shampoo together with oral medication to help reduce the amount of fungus on the scalp and lower the risk of transmitting the infection to others.

However, antifungal shampoo should not be used as the only treatment because it cannot completely eliminate fungi that have entered the hair shafts and follicles.

Care for an Inflamed Scalp

If the scalp is swollen, contains pus, or develops a kerion, the doctor may consider additional treatment depending on the severity of the inflammation.

The affected area should not be squeezed, punctured, scratched, or picked. Doing so may cause wounds, increase the risk of a secondary bacterial infection, and raise the likelihood of scarring around the hair follicles.

Corticosteroid creams or combination creams containing corticosteroids should not be purchased and applied without a diagnosis. These medicines may temporarily reduce redness and itching but can allow the fungal infection to spread, alter the appearance of the rash, and make the condition more difficult to diagnose.

Reducing Transmission and Preventing Reinfection

Maintaining cleanliness and avoiding the sharing of personal items may help reduce the spread of the infection and lower the risk of reinfection. Recommended measures include:

• Do not share combs, hairbrushes, hats, towels, or pillowcases with others
• Clean combs and hair-care equipment regularly
• Wash towels, pillowcases, and bedding regularly
• Do not use clippers or hair-cutting equipment that has not been properly cleaned
• Avoid scratching or picking at the affected area
• Wash your hands after touching the scalp or applying medication as instructed
• Check whether other household members have unusual symptoms
• Take pets to a veterinarian if they have patchy hair loss or abnormal skin changes
• Complete the full course of medication prescribed by the doctor
• Attend follow-up appointments to assess the response to treatment

Household members or people living with an infected person may need to be evaluated in some cases, particularly if they develop itching, scalp flaking, or unusual hair loss.

Summary

Scalp ringworm is a fungal infection affecting the scalp, hair shafts, and hair follicles. Its symptoms may resemble dandruff, but patients often develop broken hairs, patchy hair loss, black dots on the scalp, or inflammation.

The condition can spread through contact with infected people, animals, and contaminated objects. Avoiding the sharing of personal items and cleaning hair-care equipment appropriately may help reduce transmission.

Because the fungi can enter the hair shafts, treatment usually requires oral antifungal medication under medical supervision. Anyone experiencing patchy hair loss, scalp swelling, pain, pus, or symptoms that do not improve should not attempt to treat the condition independently and should consult a doctor for an appropriate diagnosis and treatment.

Prepared by: พญ. นัทจิรา จียาศักดิ์

References:, Centers for Disease Control and Prevention. Treatment of Ringworm, National Health Service. Ringworm, American Academy of Dermatology Association. Ringworm: Signs and Symptoms