Patients Without a Rheumatic Disease Diagnosis in a Pediatric Rheumatology Unit: Retrospective Analysis and Comparison Between Pre-pandemic and Pandemic Periods.

OBJECTIVE: Children with suspicious complaints of rheumatic diseases are generally referred to a pediatric rheumatologist. We aimed to evaluate the profile of patients referred to the pediatric rheumatology unit and were not diagnosed with a rheumatic disease and to assess the impact of the coronavirus disease-2019 pandemic on referral complaints. MATERIALS AND METHODS: All new outpatients who applied to the pediatric rheumatology department between March 2019 and February 2021 and were not diagnosed with rheumatic disease were included. We also compared the frequency of admission symptoms during the pre-pandemic (March 2019-February 2020) and pandemic periods (March 2020-February 2021). RESULTS: A total of 1089 patients without a rheumatic disease diagnosis (568 female, 52.2%; median age 10.0 years) were included in this study. The most common complaint for referral was prolonged or recurrent fevers (13.4%) followed by anti-nuclear antibody positivity (13.1%), arthralgia (13.0%), skin findings (7.5%), and the presence of heterozygous mutations in the Mediterranean fever gene (6.9%). During the pandemic year, the number of patients referred for back pain increased significantly (P = .028). A total of 682 of 1089 patients were consulted from other departments in our center (62.6%). Of these, the most frequent consultation request was from general pediatrics (43.6%). The rheumatic disease was excluded in 11.3% of the patients. CONCLUSION: Prolonged or recurrent fever and anti-nuclear antibody positivity were the most frequent complaints of referrals to a pediatric rheumatology unit in patients who did not have a rheumatic disease. The rate of back pain was more common in children during the pandemic period.

Challenges in diagnosing COVID-19 related disease in pediatric patients with rheumatic disease.

OBJECTIVES: Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe condition associated with coronavirus disease 2019. Here we aimed to raise awareness for the symptoms of MIS-C in patients with rheumatic diseases, emphasizing the challenges of the differential features. METHODS: We retrospectively evaluated the demographic and clinical characteristics, laboratory and imaging findings, treatments, and outcomes of six MIS-C patients with previous rheumatic disease. RESULTS: Three of the patients had familial Mediterranean fever (FMF), one had juvenile dermatomyositis, one had systemic juvenile idiopathic arthritis (JIA), and another patient had oligoarticular JIA. All FMF patients presented with fever and abdominal pain, two also had chest pain. The patient with systemic JIA presented with fever, rash, and myalgia. All patients had elevated inflammatory markers and high d-dimer levels. Chest imaging of two FMF patients showed infiltrations compatible with pneumonia. One FMF patient had mildly decreased systolic functions with a shortening fraction of 48% in his echocardiography. Intravenous immunoglobulin and methylprednisolone were administered to all patients. Anakinra was given to four patients. CONCLUSIONS: Clinical and laboratory signs of MIS-C may overlap with the findings of various rheumatic diseases, and this may cause a delay in diagnosis.

Differences and similarities of multisystem inflammatory syndrome in children, Kawasaki disease and macrophage activating syndrome due to systemic juvenile idiopathic arthritis: a comparative study.

To compare the clinical and laboratory findings of multisystem inflammatory syndrome in children (MIS-C), patients with Kawasaki disease (KD) and with macrophage activating syndrome due to systemic juvenile idiopathic arthritis (sJIA-MAS) on real-life data. Patients diagnosed with MIS-C, KD, and sJIA-MAS from 12 different centers in Turkey who were followed for at least 6 months were included in the study. Demographic, clinical, and laboratory findings of all patients were analyzed. A total of 154 MIS-C, 59 KD, and 31 sJIA-MAS patients were included. The median age of patients with MIS-C were higher than those with KD while lower than those with sJIA-MAS (8.2, 3, 12 years, respectively). Myalgia (39.6%), cardiac (50.6%), gastrointestinal (72.7%), and neurological (22.1%) involvements were more common in patients with MIS-C compared to others. MIS-C patients had lower levels of lymphocyte (950 vs 1700 cells/µl) and thrombocyte (173,000 vs 355,000 cells/µl) counts and higher pro-BNP (1108 vs 55 pg/ml) levels than KD. Ferritin levels were higher in patients with MIS-C compared to patients with KD while they were lower than patients with sJIA-MAS (440, 170, 10,442 ng/ml, respectively). Patients with MIS-C had a shorter duration of hospitalization than sJIA-MAS (p = 0.02) while they required intensive care unit admission more frequently (55 vs 8 patients, p < 0.001). The median MAS/sJIA score of MIS-C patients was - 1.64 (- 5.23 to 9.68) and the median MAS/sJIA score of sJIA-MAS patients was -2.81 ([- 3.79] to [- 1.27]). MIS-C patients displayed certain differences in clinical and laboratory features when compared to KD and sJIA-MAS. Definition of the differences and similarities between MIS-C and the other intense inflammatory syndromes of childhood such as KD and MAS will help the clinicians while making timely diagnosis.