Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome (PFAPA) are the most common autoinflammatory syndromes in children. This study aimed to evaluate the clinical and laboratory parameters that may predict colchicine responsiveness.This retrospective, multicenter, cross-sectional study involved nine pediatric rheumatology centers from our country., The patients diagnosed with PFAPA were compared on the basis of their responses to colchicine. In the 806 (42.3% female 57.7% male) patients, the most common clinical findings were fever (100%), exudative tonsillitis (86.5%), pharyngitis (80.9%), and aphthous stomatitis (50.5%). The mean attack frequency was 13.5 ± 6.8 attacks per year lasting for a mean of 3.9 ± 1.1 days. Colchicine treatment was attempted in 519 (64.4%) patients, with 419 (80.7%) showing a favorable response. In patients who underwent MEFV gene analysis (70.8%), the most common variant was M694V heterozygous (16.8%). The presence of pharyngitis (p = 0.03, 95% CI 0.885 to 0.994), the presence of arthralgia (p = 0.04, 95% CI 0.169 to 0.958), and having more frequent attacks (p = 0.001, 95% CI 0.028 to 0.748) were found to be associated with colchicine unresponsiveness, whereas the carriage of the M694V variant (p = 0.001, 95% CI 0.065 to 0.242) was associated with colchicine responsiveness.Conclusion: This study identified the presence of pharyngitis, arthralgia, and increased attack frequency in patients with PFAPA as factors predicting colchicine unresponsiveness, whereas the carriage of the M694V variant emerged as a predictor of colchicine responsiveness. Predicting colchicine response at disease onset may facilitate a more effective management of PFAPA. What is Known:• Colchicine treatment can be used in the prophylaxis of PFAPA disease.• Having the MEFV variant is the most commonly known factor in predicting response to colchicine. What is New:• The presence of pharyngitis or arthralgia, and more frequent attacks in PFAPA disease were found to be independently associated with colchicine unresponsiveness. • Carrying the M694V variant was identified as the sole factor predicting colchicine responsiveness.

Background: In colchicine-resistant patients with familial Mediterranean fever (FMF), alternative therapies, which are administered parenterally, become necessary. Effective pain management is essential for FMF treatment. Buzzy® (Pain Care Labs, Atlanta, GA) is specifically designed to alleviate pain during needle procedures. This innovative tool integrates a cold pack with a vibration motor, thereby enabling the simultaneous application of cold therapy, tactile stimulation, and distraction techniques. By harnessing the combined effects of cold and vibration on the skin, Buzzy® significantly reduces pain perception. This study aimed to evaluate the effectiveness of Buzzy® in mitigating pain during subcutaneous administration of canakinumab in patients with FMF who are resistant to colchicine. This study included patients with colchicine resistance who were receiving canakinumab. Pain scores were evaluated before and after applying Buzzy® using the Visual Analog Scale (VAS), Wong-Baker FACES Pain Rating Scale (FPS-R), and Children’s Fear Scale (CFS). Results: A total of 15 patients were included in the study. Nine patients (60%) were female, and six (40%) were male. The median age of the patients was nine years (five to 18 years). The median VAS, FPS-R, and CFS scores before Buzzy® were four (0 to eight), four (0 to eight), and one (0 to four), respectively. After Buzzy® application, the median VAS, FPS-R, and CFS scores were two (0 to six), two (0 to six), and 0 (0 to three), respectively. The VAS and FPS-R scores showed a significant reduction (p=0.04 and p=0.008, respectively), indicating a notable decrease in pain. Although the CFS scores also decreased following the use of Buzzy®, this reduction was not statistically significant (p=0.526). Conclusion: According to the gate control theory of pain, methods like Buzzy® temporarily block pain signals from reaching the central nervous system by "closing the gates." In patients requiring continuous injections, such applications may reduce the pain and anxiety they experience.

Background/Aims: The primary objective of this investigation is to systematically assess the resemblances and distinctions between enthesitisrelated arthritis (ERA), which serves as a pediatric analog to ankylosing spondylitis (AS), and AS. Materials and Methods: A cross-sectional analysis was conducted within a pediatric rheumatology facility and an adult rheumatology institution. Demographic and clinical attributes were juxtaposed between individuals diagnosed with AS and those with ERA. Results: A cumulative total of 200 subjects (101 minors, 99 adults) were scrutinized. The prevalence of peripheral arthritis was significantly elevated in ERA (54.5%) compared to AS (21.2%, P < .001), whereas sacroiliitis, axial involvement, and morning stiffness were more prevalent in AS. Nonsteroidal anti-inflammatory drugs constituted the predominant initial therapeutic approach (99% vs. 91.9%, P = .01). Patients with ERA exhibited a higher utilization of corticosteroids (35.6% vs. 11.1%, P < .001) and diseasemodifying antirheumatic drugs (DMARDs) (87.1% vs. 60.6%, P < .001), with no notable variance in the application of biological agents. At the final follow-up assessment, 24.8% of ERA patients were free from medication, whereas no AS patients achieved a medication-free status. Conclusion: An increased volume of scientific evidence is requisite concerning the attributes of ERA, which is presently regarded predominantly within the framework of juvenile spondyloarthritis, distinguishing it from its adult counterpart; this study serves as an observational cohort investigation that underscores this imperative. Despite the observable differences and similarities between ERA and AS, further extensive studies incorporating inflammatory biomarkers are essential to ascertain whether these conditions represent discrete diseases or exist within a broader disease continuum. Cite this article as: Unan MK, Özaslan Z, Dilek G, Şahin N, Sönmez HE, Nas K. Juvenile vs. adult-onset spondyloarthritis: Uncovering similarities and differences. Arch Rheumatol. 2026;41(2):90-99.

Background: Chronic nonbacterial osteomyelitis (CNO) is a rare autoinflammatory bone disorder with heterogeneous presentations, and no disease-specific biomarker exists, making diagnosis challenging. Recently, the European Alliance of Associations for Rheumatology (EULAR) and the American College of Rheumatology (ACR) proposed new classification criteria; however, their performance relative to the established Bristol criteria has not been systematically validated. Methods: We conducted a retrospective, multicenter cohort study across 10 pediatric rheumatology centers, including 114 children with CNO and 116 controls with mimicking conditions. Demographic, clinical, laboratory, imaging, and biopsy data were systematically collected. Each participant was assessed according to both the EULAR/ACR classification and the Bristol diagnostic criteria. Sensitivity, specificity, predictive values, likelihood ratios, receiver operating characteristic (ROC) analysis, and agreement statistics were calculated using expert clinical diagnosis as the reference standard. Results: The EULAR/ACR criteria demonstrated 97.4% sensitivity and 81.0% specificity, compared with 79.8% and 80.2% for the Bristol criteria. The negative likelihood ratio was markedly lower for the EULAR/ACR criteria (0.03 vs. 0.25), underscoring their strong rule-out capacity. Concordance between systems was substantial ( κ =0.66). Discordant cases showed that the EULAR/ACR criteria better identified atypical phenotypes such as unifocal or nonclavicular disease. Elevated ESR supported the diagnosis of CNO, whereas profound anemia was almost exclusive to mimicking disorders. Conclusion: The EULAR/ACR criteria provide a more sensitive and inclusive framework for CNO while maintaining robust specificity. Their ability to capture atypical cases may reduce diagnostic delay and unnecessary biopsies, though clinical judgment remains essential in distinguishing CNO from overlapping inflammatory arthritis. Clinical Relevance: Validation of the EULAR/ACR classification criteria may facilitate earlier and more accurate classification of pediatric CNO and reduce unnecessary invasive diagnostic procedures.