The Pattern of Post-viral Arthritis in COVID Pandemic State: An Experience of Tertiary Care Centre.

Jaladhar, Prakruthi; S, Chandrashekara; Salanke, Manasa; Kori, Devaraj

BACKGROUND Acute onset polyarthritis is a common presentation in rheumatology outpatient consultations, which include both post-infectious arthritis and autoimmune rheumatic diseases (AIRDs). COVID pandemic has added to the list of infectious agents that could result in arthritis. MATERIALS AND METHODS The retrospective observational study was conducted at a tertiary care centre. The study included patients who presented with clinical suspicion of post-infectious arthritis between July-September 2019 and 2020. The study was extended for another 2 months to include patients who presented between October-November 2020. The patients were categorized into post-viral arthritis, post-COVID arthritis, chikungunya arthritis and AIRDs. The demographics, comorbidities, clinical presentation, examination findings and laboratory parameters and the response to treatment for each participant were collected and assessed. RESULTS In the year 2019 and 2020 (July-Sep), the corresponding number of patients analyzed were 20 and 33. The mean duration of presentation was 1.53 (±3.10) weeks. Chikungunya arthritis was noted in 10% of patients in 2019, while it was 15.15% in 2020. Other post-viral arthritis was identified in 65% and 66.67% of patients in 2019 and 2020 respectively. In the second part of the study, 65.68% of patients were classified as post-viral arthritis, including chikungunya arthritis, post-COVID arthritis and other post-viral arthritis. Around 27% were categorized as AIRDs. Rheumatoid factor negativity and anti-nuclear antibody negativity were found to be significant (P 0.0) in categorizing the patients into post-viral arthritis group, while presence of urinary symptoms (P 0.0) classified the patients into reactive arthritis. CONCLUSION The study revealed that the presence of chikungunya arthritis across the two years was comparable. Post-COVID arthritis needs to be considered as a potential differential in post-infectious arthritis. There are no identifiable characteristics (clinical or a simple routine laboratory parameter) that could differentiate the causes of post-infectious arthritis from AIRDs.