Although it is still rare, childhood melanoma is on the rise, according to a new study in the May 2013 issue of Pediatrics.

The rate increased by about 2% per year from 1973 to 2009 among US children aged 0 to 19, the study showed. In all, 1,317 children were diagnosed with melanoma during this 30-year time frame.

Researchers used Surveillance, Epidemiolgy and End Results (SEER) data to capture trends in childhood melanoma. The greatest increase was seen among adolescents aged 15 to 19, especially girls. According to the findings, boys were more likely to develop melanomas on their face and trunks, while girls were more likely to have melanoma on their lower legs and hips.

Researchers can only speculate about why childhood melanoma is increasing. Possibilities include temporal changes in the prevalence of melanoma risk factors such as increased ultraviolet exposure from sunlight and tanning beds, increased melanoma case ascertainment, and/or overdiagnosis. “Similar to recent adult patterns, our analyses indicate melanoma incidence is increasing among adolescents,” the researchers conclude.