Ringworm of the scalp is not really a worm, but a fungal infection. Also called Tinea capitis, this infection affects both your scalp and hair shafts, causing small patches of itchy, scaly skin on the scalp. It gets the name “ringworm” because the fungus makes circular marks on the skin. Ringworm is a highly contagious infection that is usually spread through person-to-person contact or by sharing combs, towels, or pillows. Ringworm is most common in children, but can infect a person of any age.
Fungi called dermatophytes cause ringworm of the scalp. Fungi are organisms that thrive on dead tissue, such as fingernails, hair, and the outer layers of your skin.
Ringworm spreads easily, especially among children. You can get ringworm from contact with the skin of an infected person. If you use combs, bedding, or other objects that have been used by an infected person, you are also at risk. House pets, such as kittens and puppies, can also spread ringworm. Farm animals like goats, cows, horses, and pigs can also be carriers. These animals might not show any signs of infection.
Overcrowding and poor hygiene increase the spread of ringworm. Since dermatophytes prefer warmth and moisture, ringworm thrives on sweaty skin.
The most common symptom of ringworm is itchy patches on the scalp. Sections of hair may break off at or close to the scalp, leaving scaly, red areas or bald spots. Left untreated, these areas gradually grow. Other symptoms include:
- brittle hair
- painful scalp
- swollen lymph nodes (vessels that help the body fight off infection)
- low-grade fever
In more severe cases, you may develop kerion, which are crusty swellings that drain pus. These can lead to permanent bald spots and scarring.
A visual exam is often enough for a doctor to diagnose ringworm of the scalp. Your doctor may use a special light called a Wood’s lamp to illuminate your scalp and determine signs of infection.
Your doctor may also take a skin or hair sample to confirm the diagnosis. This involves taking a hair or scraping from a scaly patch of scalp and looking at it under a microscope. The sample is then sent to a lab to determine the presence of fungi. This process may take up to three weeks (NLM, 2010)
Your doctor will probably prescribe fungi-killing oral medication and medicated shampoo.
The leading antifungal medications for ringworm are griseofulvin and terbinafine hydrochloride. The Children’s Hospitals and Clinics of Minnesota recommend taking these medications with a high-fat food like peanut butter or ice cream (CHCM, 2009). Both are taken orally for approximately six weeks. Both have common side effects, including diarrhea and upset stomach.
Other possible side effects of griseofulvin (sold as Grifulvin V, Gris-PEG) include:
- light sensitivity
- faintness and dizziness
- allergic reactions in people who are also allergic to Penicillin
Other possible side effects of terbinafine hydrochloride (sold as Lamisil) include:
To remove fungus and prevent the spread of infection, your doctor may prescribe a medicated shampoo that contains at least two-and-a-half percent selenium sulfide, the active antifungal ingredient. Leave the shampoo on for five minutes, then rinse. Your doctor may tell you to use this shampoo a couple of times a week for a month. Medicated shampoo helps prevent the fungus from spreading, but it is not enough to kill ringworm. This type of treatment has to be combined with oral medication.
Recovery and Prevention of Reinfection
Ringworm heals very slowly—it can take more than a month to see any improvement. Be patient and continue taking all medication as directed. In the meantime, you may want to wear a scarf or hat to cover bald patches.
If you’re treating a child for ringworm, ask the doctor when he or she can safely return to school without being a threat to others.
Pets and other family members should be examined and, if necessary, treated. This will help prevent reinfection. Do not share towels, combs, hats, or other personal items with other family members. You can sterilize combs and brushes of the infected party by soaking them in bleach water.
It’s hard to get rid of ringworm. Once you do, it might recur; however, recurrences often stop at puberty. Long-term effects include possible bald patches or scarring.
The dermatophytes that cause ringworm are both common and contagious, making prevention difficult. Since children are especially susceptible, tell your children about the risks of sharing hairbrushes and other personal items. Regular shampooing, hand washing, and other normal hygiene routines can help prevent the spread of infection.
While you can’t always tell if an animal has ringworm, bald patches are a common sign of infection. Avoid petting animals where patches of skin show through the fur. Maintain regular checkups for all pets and ask your veterinarian to check for ringworm.