- Round patches of hair loss that slowly increase in size
- A black-dot, stubbled appearance of the scalp from hair shafts that are broken off at the surface
- The scalp may have scaling
- Mild itching of the scalp
- Ringworm of the face may also be present
- Usually occurs in children age 2 to 10 years
- This diagnosis requires a positive microscope test (potassium hydroxide [KOH prep]) or fungus culture.
A fungus infects the hairs and causes them to break. Ringworm is not caused by a worm. Over 90% of cases are due to Trichophyton tonsurans, which is transmitted from other children who are infected. Combs, brushes, hats, barrettes, seat backs, pillows, and bath towels can transmit the fungus. Less than 10% of the cases are caused by infected animals. The animal type causes more scalp irritation, redness, and scaling. If your child has the animal type of fungus, he is not contagious to other children.
Ringworm of the scalp is not dangerous. Without treatment, however, the hair loss and scaling may spread to other parts of the scalp. Some children develop a kerion, which is a boggy, tender swelling of the scalp that can drain pus. Kerions are an allergic reaction to the fungus and may require additional treatment with an oral steroid. Hair regrowth is normal after treatment but will take 6 to 12 months. In the meantime, your child can wear a hat or scarf to hide the bald areas.
Oral Antifungal Medicine. The main treatment for ringworm of the scalp is griseofulvin taken orally for 8 weeks. Griseofulvin is best absorbed if taken with fatty foods such as milk or ice cream. Antifungal creams or ointments are not effective in killing the fungus that causes ringworm of the scalp.
Antifungal Shampoo. The use of an antifungal shampoo makes your child less contagious and allows him to return to day care or school. Purchase a nonprescription shampoo containing selenium sulfide (e.g., Selsun). Lather up and leave it on for 10 minutes before rinsing. Use the antifungal shampoo twice a week for the next 8 weeks. On other days, use a regular shampoo.
Contagiousness. Ringworm is mildly contagious. In the days before antifungal medications, about 5% of school contacts usually became infected. However, 25% of siblings (close contacts) developed ringworm. Once your child has been started on griseofulvin and received one washing with the special shampoo, he can return to school. Caution your child not to share combs or caps with other children. Check the scalps of your child's siblings. If you see any scaling or patches of hair loss, refer that child to their doctor's office.
Common Mistakes. It is psychologically harmful and unnecessary to shave the hair, give a close haircut, or to force your child to wear a protective skull cap.
Follow-up Appointment. In 4 weeks return for lab tests of your child's hair to be certain we have achieved a cure. If not, the griseofulvin will need to be given for longer than 8 weeks.
CALL OUR OFFICE
During regular hours if
- The ringworm looks infected with pus or a yellow crust.
- The scalp becomes swollen or boggy.
- The ringworm continues to spread after 2 weeks of treatment.
- You have questions or concerns.
Instructions for Pediatric Patients, 2nd Edition, ©1999 by WB Saunders Company.
Written by Barton D. Schmitt, MD, pediatrician and author of Your Child’s Health, Bantam Books, a book for parents.