Ringworm of the scalp (tinea capitis) is a rash caused by a fungal infection. It usually causes itchy, scaly, bald patches on the head. Ringworm gets its name because of its circular appearance. No worm is involved.

Ringworm of the scalp appears as round patches where the hair has broken off at or just above the scalp. These bald-looking patches slowly grow larger.
Ringworm of the scalp is a contagious infection. It's most common in toddlers and school-age children. Tinea capitis is related to athlete's foot (tinea pedis), jock itch (tinea cruris) and ringworm of the body (tinea corporis).
Medication taken by mouth can kill the fungus that causes ringworm of the scalp. Medicated shampoos may help keep a person from spreading the infection to others.
Signs and symptoms of ringworm of the scalp may include:

Up close, the scalp can look scaly and silvery with patches of broken hair. You may also see small black dots if the hair has broken off right at the scalp.
Several conditions affecting the scalp may have a similar appearance. See your child's doctor if your child has any hair loss, scaling or itchiness of the scalp, or other unusual appearance of the scalp. It's important to get an accurate diagnosis and prompt treatment with prescription medicine. Nonprescription creams, lotions and powders won't get rid of ringworm of the scalp.
Ringworm of the scalp is caused by a common fungus. The fungus attacks the outer layer of skin on the scalp and the hair. This causes those hairs to break. The condition can be spread in the following ways:
Risk factors for ringworm of the scalp include:
Some people with ringworm of the scalp may develop a severe inflammation called kerion. Kerion appears as soft, raised swellings that drain pus and cause thick, yellow crusting on the scalp.

Ringworm of the scalp can cause kerion a severe, painful inflammation of the scalp. Kerion appears as soft, raised swellings that drain pus.
With kerion, the hair falls out or can be easily pulled out. The condition may be caused by an overly vigorous reaction to the fungus and can lead to scarring and permanent hair loss.
Ringworm of the scalp is difficult to prevent. The fungus that causes it is common, and the condition is contagious even before symptoms appear. Take these steps to reduce the risk of ringworm: