It's a warm September night in Southeast Texas. The crowd is humming with excitement over two evenly matched teams locked in a tight battle. The running back sprints out of the backfield, catches a perfectly lofted pass, and is tackled hard after the gain. He stays down after the hit, and the medical staff rushes onto the field. Our first question is: “Where does it hurt? What happened?”
In my pediatric sports medicine practice, this situation plays out every Friday night during the fall. As a team physician, I ascertain the injury mechanism and the location of the injury. “Point to where it hurts” is a good first step in establishing the diagnosis. The difficulty lies in the adrenaline of the moment, the emotions of the injured athlete, and the initial uncertainty of the injury severity.
Often the patients in our pediatric offices are complicated in a different manner. There are complicated histories and an array of labs, imaging, and previous workups to sift through. In sports medicine we are cognizant of the injury mimics, whether it be rheumatologic, infectious, or oncologic causes. It is medical detective work that can lead to dead ends but makes establishing a diagnosis that much more rewarding.
The January issue of Pediatrics in Review features three cases of joint pain where this detective work plays out.
In a case of elbow arthritis by Bao et al., we read about the atraumatic swollen elbow. Septic arthritis and osteomyelitis can present without inciting trauma, but as it turns out, Lyme arthritis was the surprising diagnosis. In areas endemic with Lyme, this should be kept in the joint pain differential much as Coccidioidomycosis in the southwest, or Blastomycosis in the midwestern and southern river valleys of the United States.
Kushnir et al. present another fascinating case with an unexpected twist. Despite an earlier diagnosis of patellofemoral pain syndrome (a common sports medicine diagnosis), the patient’s bilateral knee pain turns out to be drug-induced lupus. The new medicine used to treat the patient’s seizures was implicated. The determining clues came in the patient history: the initiation of a new anti-epileptic, and the systemic symptoms involved.
In the last case, Nguyen et al. note that rheumatic fever has a high global burden and should still be kept on our differential of joint pain as it is a minor criterion of the revised diagnostic Jones criteria. It is a reminder of why the recognition and treatment of group A streptococcal (GAS) infections is important to prevent these potential downstream post-infectious complications. In my sports medicine clinical practice, I’ve seen numerous circumstances of GAS osteomyelitis and septic arthritis after a seemingly innocuous infection.
Dr. Ramirez weighs in on these cases in his analysis and offers a great reminder of the importance in keeping a broad differential and taking a detailed history. Diagnostic imaging and studies are often helpful, but as we teach our pediatric trainees, history and then a comprehensive physical exam will direct us to the diagnosis. We just need to take the time to look and listen.