Symptoms and causes

Symptoms

The signs and symptoms of ringworm of the scalp include:

  • One or more round patches of scaly skin where the hair has broken off at or just above the scalp
  • Patches that slowly expand or enlarge
  • Scaly, gray or reddened areas
  • Patches that have small black dots where the hair has broken off at the scalp
  • Brittle or fragile hair that easily pulls out
  • Tender or painful areas on the scalp<

When to see a doctor

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, appropriate treatment.

Causes

Ringworm of the scalp is caused by one of several varieties of mold-like fungi called dermatophytes. The fungi attack the outer layer of skin on the scalp and the hair shaft.

Ringworm isn't caused by a worm. The common name for the disorder refers to the ring-like or circular appearance of the infection on the skin.

Methods of transmission

Ringworm is contagious and can spread in the following ways:

  • Human to human. Ringworm often spreads through direct skin-to-skin contact with an infected person.
  • Object to human. Ringworm can spread through contact with objects or surfaces that an infected person or animal has touched, such as clothing, towels, bed linens, combs or brushes.
  • Animal to human. Dogs and cats, especially puppies and kittens, are often carriers of ringworm. Other animals that are often carriers of the fungi include cows, goats, pigs and horses. Your child can contract ringworm by grooming or petting an animal with ringworm.

Other types of ringworm

The fungi that cause ringworm of the scalp can cause other infections on the body. These infections are generally classified by the part of the body affected. They include:

  • Ringworm of the body (tinea corporis). This form causes a red, scaly ring or circle of rash on the top layer of your skin.
  • Athlete's foot (tinea pedis). This form of ringworm affects the moist areas between your toes and sometimes on the foot itself.
  • Jock itch (tinea cruris). This form affects your genitals, inner upper thighs and buttocks.

Risk factors

Risk factors for ringworm of the scalp include:

  • Age. Ringworm of the scalp is most common in toddlers and school-age children.
  • Exposure to other children. Outbreaks of ringworm are common in schools and child care centers where the infection easily spreads through close physical contact.
  • Exposure to pets. A pet, such as a cat or dog, can have the infection without showing any signs. Children can get the infection by touching or petting the animal.

Complications

In some cases, ringworm of the scalp causes kerion — a severe, painful inflammation of the scalp. Kerion appears as soft, raised swellings that drain pus and cause thick, yellow crusting on the scalp.

Instead of breaking, the hair falls out or can be easily pulled out. Kerion may be caused by an overly vigorous reaction to the fungus and can lead to permanent scars and hair loss.