However, none of the children, according to the CDC report, showed signs of illness beyond a rash.

State and local health departments in 27 states have been investigating unexplained rashes among US schoolchildren since October of last year, according to CDC's report in the June 21st issue of the Morbidity and Mortality Weekly Report.

The CDC notes that rashes, which are common among school-aged children, were reported at 110 US elementary, middle and high schools between October 2001 and May 2002, with the number affected at each school ranging from 5 to 274.

In the current article, the CDC describes investigations taking place in 3 of the 27 states: New York, Georgia and Missouri.

Although the characteristics of the rashes vary, the CDC describes them as "sunburn-like." The rashes appeared on children's cheeks and arms, sometimes in a network-like pattern, and often caused a burning sensation. They lasted from less than 1 hour to longer than 1 month.

Health Department officials in New York sent out notices in March 2002 to school officials to increase awareness and reporting of rash outbreaks. The ongoing investigation there, which began in January, identified rashes in 242 elementary- and middle-school students in a school district with 3371 children. Children, parents, school nurses and local doctors were interviewed, and various viral cultures of throat and stool specimens were taken.

"The results of this investigation support the conclusion that the outbreak was due to parvovirus B19," which can trigger "fifth disease" in children, a mild illness characterized by a transient rash, according to the CDC's report.

In Georgia, the report on 12 children who developed rashes for a single day states that the rashes were likely caused by "scratching secondary to observing, encountering, or interacting with [a child with an] eczematic rash."

Contact dermatitis was "the most likely explanation" in the case of a rash outbreak among 33 children in Missouri earlier this year. The report notes that handling of cleaners and alcohol-based sanitizers or surface cleaners may have been the source.

"CDC is continuing to monitor reports of rashes and is providing technical assistance to state and local health departments investigating these reports," the agency added.

MMWR 2002;51:524-526.