"Back pain is common in adults, and the majority of the time, it's nothing serious. But when children complain, doctors and parents should be concerned." — Vesna Martich Kriss, MD, Associate Professor of Radiology and Pediatrics at the University of Kentucky College of Medicine.

A child who complains of an aching back shouldn't be ignored, even if an initial x-ray exam doesn't reveal a problem. When children complain of back pain, about a third of the time there's a serious reason, whether due to an injury, infection or a tumor.

"Back pain is common in adults, and the majority of the time, it's nothing serious," said Vesna Martich Kriss, MD, an associate professor of radiology and pediatrics at the University of Kentucky College of Medicine. "But when children complain, doctors and parents should be concerned."

"Even if an initial x-ray doesn't show anything, parents shouldn't stop there if pain persists," she said. "For instance, sometimes a fracture after a trauma doesn't show up in an x-ray for a week or two. A second x-ray may be necessary if the child continues to complain, and occasionally, a bone scan may be necessary to get to the root of the problem." Adolescent athletes, gymnasts in particular, are prone to back injuries because they're often competing at high levels and putting stress on immature bones, Kriss said.

Other potential problems include infection and bone tumors. Osteomyelitis is a bone infection that can not only interfere with growth but also can destroy bone. Although not common among healthy kids, only several thousand children contract it annually, the infection is serious and must be treated before it causes permanent damage to the bone. And while cancer is rare in adolescents, bone tumors are one of the most common tumors in that group, with about 900 new cases every year. It is twice as common in males as in females.

In a study performed in the United Kingdom, of 69 children complaining of low back pain, 21 were identified as having back lesions by bone scan, or a single photon emission computed tomography (SPECT), while x-ray detected problems in only 8 children.

In a bone scan, the patient is injected with a radioactive tracer, which collects in the areas of the bone with high activity, caused by tumor, infection or trauma. The patient lies under a device called a gamma camera, which detects where the tracer has accumulated. "Abnormalities often light up like a light bulb," Kriss said.

"Once the skeleton matures when the child reaches approximately age 18, then they're in the adult realm, and back pain becomes less of a concern," she said.