April 19, 2010 -- Many children attending elementary schools are infected
with a fungus that is the leading cause of ringworm in the U.S., a new study
The finding comes from a study of 10,514 children in kindergarten through
fifth grade in 44 schools in the Kansas City metropolitan area.
Researchers found that almost 7% of children were infected on their scalps
with Trichophyton tonsurans, a fungus that is the leading cause of
ringworm in the U.S.
Researchers say the study, the largest of its kind aimed at defining
infection prevalence of kids in metro areas, has implications for children
across the country.
"The organism T. tonsurans has become the leading cause of scalp
infection in the U.S., and we believe it is on the rise in inner city areas,"
Susan Abdel-Rahman, PharmD, of Children's Mercy Hospitals and Clinics in Kansas
City, says in a news release. "This study supports what I and many of my peers
are seeing -- children with scaly, itchy scalps and hair loss are prevalent in
When not treated, ringworm can lead to permanent hair loss, which can damage
a child's self-image, she says. "There is also some evidence that it may worsen
seemingly unrelated problems, such as asthma and allergic rhinitis."
Ringworm is caused by a fungus, not by a worm. In the past, the main cause
of ringworm was caused by a species of fungus called microsporum that often
passed to humans from cats and dogs, Abdel-Rahman says. But Trichophyton
tonsurans has emerged in recent years, and it spreads directly between
humans. It also is more difficult to find and treat.
Infection rates in this study varied considerably based on race and age.
African-American children were found to be at greatest risk.
The study found that:
Infection rates at participating schools ranged from 0% to 19.4%.
Infection rates were greater than 30% in some grade levels in some
More than 18% of the youngest African-American kids evaluated, in first
grade or kindergarten, were infected.
By fifth grade, the African-American infection rate had dropped to 7%.
Overall, infection prevalence rates for African-American kids were 12.9%,
compared to 1.6% in Hispanic kids and 1.1% in white children
Researchers say the reason for the "dramatically higher" prevalence in
African-American children was not clear.
"T. tonsurans has learned how to stay on the host and avoid
eradication," Abdel-Rahman says in a news release. "This can be very
frustrating for children who keep getting re-infected and for their parents who
are doing everything they can to prevent this."
Current treatment calls for a course of oral antifungal medication, taken
for six to eight weeks, when symptoms commonly go away.
Ringworm: Avoid Sharing Hats, Combs
Abdel-Rahman says experts have only recently begun to appreciate "just how
many children carry this pathogen," so they aren't sure yet how best to tackle
"However, I do advise parents to limit the sharing of items that come into
contact with the scalp, such as hats, combs, brushes and pillows," she says.
"Watch closely for signs of infection, such as flaking that looks like
dandruff, white patchy scaling, itching, hair thinning or loss and small,
pus-filled bumps, especially when your child has come in contact with another
Abdel-Rahman says parents should make arrangements for their child to see a
doctor and make sure the medicine is taken as directed, along with the
application of a medicated shampoo two to three times per week.