Limp raises suspicion for juvenile arthritis

There are a number of entities to consider in the differential diagnosis when a child presents with a limp, including autoimmune diseases, musculoskeletal disorders, infection, and cancer. From the rheumatologist’s perspective, juvenile arthritis is high on the list.

In a presentation on Sunday, October 23, titled “The limping child: Orthopedic and rheumatologic perspectives,” Kristen Hayward, MD, FAAP, assistant professor, Department of Pediatrics, Division of Rheumatology, University of Washington School of Medicine, Seattle, discussed clues that should raise suspicion of juvenile arthritis, the laboratory tests pediatricians can order as an initial diagnostic evaluation, and when referral to a subspecialist is appropriate.

“Juvenile arthritis can develop at any age and is more common than people recognize, with an estimated prevalence of about 1 in 1000 in the pediatric population,” said Hayward.

She noted that limping may be an early sign of juvenile arthritis, and the diagnosis of juvenile arthritis should be considered in a child with a persisting limp, especially if the problem is greatest in the morning and improves during the day. Other findings that support consideration of juvenile arthritis include stiffness on awakening, persistent joint pain, and changes in physical activity.

“Because the physical findings of certain kinds of arthritis may be fairly subtle, they may be missed on screening musculoskeletal physical exams.” Hayward said. “Through the general history, however, pediatricians do an excellent job in identifying changes in activity level or difficulty with school-related tasks. Although there are multiple reasons that can explain why a child may be struggling to participate in usual activities, juvenile arthritis is one cause that might not come to mind right away.”

Pediatricians can initiate a diagnostic workup by getting a good history that can help further support the diagnosis of arthritis or an alternate problem that can have overlapping symptoms, including infection or malignancies, such as leukemia. Pediatricians should ask about presence of rash, fevers, weight loss, and general growth and development.

Hayward noted that a diagnosis of juvenile arthritis is not straightforward because there is no one laboratory finding that clinches it.

“Pediatricians may order rheumatoid factor, antinuclear antibody, and anticyclic citrullinated peptide antibodies, but should be aware that these assays are more prognostic than diagnostic and that negative results do not rule out a rheumatologic disease,” she said.

After excluding other causes for limp, referral to a rheumatologist is appropriate for a child with evidence of multisystem disease or when the limp does not improve with usual first-line therapies; ie, a short course of a nonsteroidal anti-inflammatory drug with or without physical therapy.

In the same session, Brian Shaw, MD, FAAOS, FAAP, associate professor, Orthopedic Surgery, University of Colorado School of Medicine, Denver, reviewed orthopedic causes of limp and referral to an orthopedist.

Ms Krader has 30 years’ experience as a medical writer. She has worked as both a hospital pharmacist and a clinical researcher/writer for the pharmaceutical industry, and is presently a freelance writer in Deerfield, Illinois. She has nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article.