Systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still’s disease (AOSD) should be grouped into one disease, Still’s disease, according to new diagnosis and treatment recommendations presented at the annual European Congress of Rheumatology.
The recommendations, made in collaboration with EULAR and the Pediatric Rheumatology European Society, emphasized that the ultimate treatment target for Still’s disease should be drug-free remission in all patients and that macrophage activation syndrome (MAS) should be identified and treated as soon as possible.
The task force focused on MAS because despite effective, innovative therapies, “we continued to see MAS,” said presenter Bruno Fautrel, MD, Pitié-Salpêtrière University Hospital, Paris. “We have to be very concerned about this potential complication.”
Dr. Fautrel copresented the recommendations with Fabrizio De Benedetti, MD, PhD, head of the division of rheumatology, Bambino Gesù Hospital, Rome.
Diagnosis
Dr. Fautrel noted that the cutoff age of 16 that differentiates sJIA and AOSD is “arbitrary.” There are some differences in age: The frequency of the disease is higher in young children, but it plateaus in young adults. Children under 18 months old are also far more likely to develop MAS.
To diagnose and treat Still’s disease, the recommendations state that clinicians should consider four criteria:
- A fever spiking at or above 39° C (102.2° F) for at least 7 days.
- A transient rash, preferentially on the trunk, that coincides with fever spikes, rash is typically erythematous but other rashes, like urticaria, can be consistent with the diagnosis.
- Some musculoskeletal involvement is common, involving arthralgia/myalgia.
- High levels of inflammation identified by neutrophilic leukocytosis, increased serum C-reactive protein (CRP), and ferritin.
Dr. Fautrel noted that, while arthritis can be present, it is not necessary to make a diagnosis. In pediatrics, “arthritis is likely to happen after a few weeks of the evolution of the disease,” and waiting for arthritis to develop can lead to diagnostic delay, “which is a problem.”
For individuals with suspected Still’s disease, NSAIDs can be used as a “bridging therapy” before the diagnosis is confirmed.
Treatment
The recommendations emphasized that treatment and therapeutic strategy “should be based on shared decision-making between the parents/patients and the treating team,” with the ultimate goal of drug-free remission.
To achieve this goal, the document outlines time-based targets for clinically inactive disease (CID). At 4 weeks, patients should have no fever, reduction of active or swollen joint count by more than 50%, a normal CRP level, and a rating of less than 20 on a visual analog scale of 0-100. At 3 months, patients should maintain clinically inactive disease with a glucocorticoid dose of less than 0.1 or 0.2 mg/kg per day. At 6 months, CID should be maintained without glucocorticoids.
While the authors of the recommendations noted that glucocorticoids are efficacious, their long-term use should be avoided because of safety issues. An interleukin-1 or IL-6 inhibitor should be prioritized and initiated as soon as possible after diagnosis.
Patients should maintain CID between 3 and 6 months before tapering off biologics.
Dr. Karen Onel
The recommendations are congruent with the 2021 American College of Rheumatology’s guidelines for sJIA, noted Karen Onel, MD, pediatric rheumatologist, Hospital for Special Surgery, New York, and the principle investigator for the ACR guidelines. One main difference is that the EULAR recommendations included time lines for treatment targets, while the ACR’s did not.
“It’s great to have these time lines in there,” she said in an interview, though there are still some unknowns. “We don’t actually know what the tapering frequency should be,” she said, “but these are definitely goals that we need to explore and see how they evolve.”