Background:Fever without a source (FWS) is caused by various diseases, making differential diagnosis difficult. Clinical similarities between Kawasaki disease (KD) and systemic Juvenile Idiopathic Arthritis (sJIA) are well known. Kawasaki disease (KD), a self-limiting systemic vasculitis, remains of unknown etiology and can cause irreversible coronary artery aneurysms (CAAs). SoJIA is sometimes confused with incomplete KD because both diseases have overlapping clinical features and can be accompanied with CAAs and/or SJIA with macrophage activation syndrome (MAS).Objectives:In this study, the frequency of both KD and SJIA among the patients evaluated with FWS and the clinical features of patients diagnosed with Kawasaki disease.Methods:Medical records of patients who first visited our department between January 2016 and December 2019 were reviewedResults:A total of 107 patients were enrolled in this study, including 43 patients (40.2%, 23 males) who fulfilled the criteria of Kawasaki disease and 64 patients (59.8%, 39 males) who did not fulfill them. In patients who fulfilled the criteria of classical FWS, 36(33.6%, 20 males) patients were diagnosed with systemic juvenile idiopathic arthritis. The mean age of the patients with Kawasaki disease was 30.0±20,4 months (median 25 months), the mean age of other patients was 52,6±40 months (median 39,5 months). The mean age of the patients with sJIA patients was 87,6±49,8 (median 80months). Kawasaki patients were younger than others (p=0.01). There was no difference in gender between groups.In Kawasaki patients, the most common clinical feature at diagnosis was fever (100%) followed by conjunctival congestion and mucosal changes (69%). The last two findings are more significant in kawasaki patients than others (p<0,00). Twenty-six (59%) patients had completed KD while 25% had incomplete KD. 7 (16%) patients had atypical KD. The mean fever duration was longer in sJIA patients than KD and others (median 14,8 and 7 days, p<0.00). All patients with KD received IVIG (2 g/kg, infusion in 12 h) and aspirin (60 mg/kg/day). 13.6% of the patients also received oral corticosteroids because of IVIG resistance. Thirty-one patients (72.1%) responded to IVIG treatment, whereas 12 (6 female, 6 male) were IVIG resistant. CAI was detected in echocardiography at diagnosis in 10 (22.7%) (6 female; 4 male) patients. We also detected 4 patients pericarditis with /without CIA.Conclusion:The clinical presentations of KD and sJIA are quite similar with fever, rash, hepatomegaly, and lymphadenopathy. All 2 entities may provide clues to potentially shared immunopathology.References:[1]Arslanoglu Aydin E et al. The factors affecting the disease course in Kawasaki disease. Rheumatol Int. 2019 Aug;39(8):1343-1349[2]Dong S et al. Diagnosis of systemic-onset juvenile idiopathic arthritis after treatment for presumed Kawasaki disease. J Pediatr. 2015 May;166(5):1283-8.Disclosure of Interests:None declared
Tocilizumab modifies clinical and laboratory features of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis