The 7-year-old boy had some of the classic symptoms of systemic onset juvenile rheumatoid arthritis, or JRA, including unresolved fever over two weeks, and arthralgias and rash that seemed to worsen with the fever spikes. Extensive workups at both an outside hospital and at Hopkins Children’s showed pleural and pericardial effusion, elevated inflammatory markers, and a family history notable for a maternal aunt with rheumatoid arthritis – features all consistent with systemic JRA. Also, abdominal ultrasounds and lab tests had already ruled out appendicitis or flu in this young patient. A positive streptococcal throat culture was thought to represent a “carrier state.” 

“There didn’t appear to be an infectious process,” noted pediatric resident Alisa Khan in presenting the case at a recent noon conference at Hopkins Children’s.  

But, added pediatric rheumatologist Edward Sills, “If you walk out of the conference thinking of this as a typical case of juvenile rheumatoid arthritis, you’ll walk out with the wrong idea. It may well be JRA, but there are several things in this case that really are atypical.” 

One was what the child’s parents described as “excruciating” abdominal pain, which Sills noted is seldom seen in JRA. Also, the child’s persistent but sporadic fevers didn’t fit the predictable pattern of fevers associated with JRA, which typically occur in a precise diurnal pattern. 

“When the child with JRA has fever both his rash and irritable personality are flagrantly obvious, but within 3 to 4 hours, regardless of whether or not you intervene, the fever is gone and the child is back to baseline and happy,” Sills noted. “Then, at the same time as the previous day, the fever spikes. You can set your clock to it.” 

Also, while the pericardial effusion was the most alarming concern because it’s associated with life-threatening cardiac tamponade, in which a large amount of fluid inside the sac around the heart disrupts cardiac function, ultrasound imaging showed that the effusion was very small and not in an area commonly associated with tamponade. Another atypical feature in this case was the child’s immediate response to the initial dose of non-steroid anti-inflammatories, which doesn’t happen in JRA. Even steroids, Sills stressed, take hours to days to suppress the fevers. The fact that the child’s abdominal pain, fever and rash improved may be related to antibiotics he had received over the weeks leading up to and during his admission, pointing to a possible infection after all. 

“Indeed, this might have been a GI infection with bacterial origin that may or may not have responded to the antibiotics,” said Sills. “But we don’t know, and we’ll have to follow him for a relatively long period of time.” 

One take-away for pediatricians? Be aware that all forms of JRA are not the same – they are distinguished by the number of joints involved initially, age of onset, gender predominance, and the severity of presentation. Some forms of JRA, for example, are also associated with anterior uveitis, an inflammatory disease of the eye that may result in vision loss if not properly and promptly treated. Pediatricians, Sills added, might want to think outside the box about other possibilities besides JRA, which tends to be generalized and over-diagnosed. 

“Importantly, probably half or more of the children who are so-labeled with JRA don’t have it,” Sills noted. “It’s easy and convenient to put a child like this in this diagnostic box, prescribe the medicines and not think about what else it could be. If an illness presentation is diagnosed as ‘atypical X,’ it is very likely not ‘X.’”