New-onset inflammatory arthritis after COVID-19 vaccination: A systematic review

Aim: To analyze the clinical patterns of new-onset inflammatory arthritis after COVID-19 vaccination among patients without pre-existing rheumatic or autoimmune diseases. Method: Case reports and series of new-onset inflammatory arthritis after COVID-19 vaccination were collected before April 2022. Clinical characteristics including diagnosis, age, gender, vaccine types, time interval between events, joint involvement (poly- or oligo−/monoarthritis), and laboratory data reflecting inflammatory status were sorted and P values between these parameters are calculated with independent sample Student's t test or 2 × 2 Fisher's exact test. Results: Among 39 cases with new-onset post-vaccination arthritis including 25 females and 13 males (1 unknown), the most common diagnosis is adult-onset Still's disease (AoSD, 10 cases), and the most common vaccine types are BNT162b2 (16 cases) and AZD-1222 (or ChAdOx1-nCoV19, 15 cases). Sub-analysis reveals that post-vaccination polyarthritis is more common among females (P =.016, by 2 × 2 Fisher's exact test, compared with male patients) and older patients (P =.006, by Student's t test). The C-reactive protein level is significantly higher in cases with post-vaccination inflammatory polyarthritis than oligoarthritis (P =.029), as well as in cases with AoSD than other causes of post-vaccination arthritis (P =.004). However, serum level of erythrocyte sedimentation rate in patients with post-vaccination AoSD are independent of other clinical variables in the analysis. Conclusion: New-onset post-vaccination polyarthritis are more common in females and older patients. Although COVID-19 vaccines may lead to inflammatory arthritis, the benefits of vaccination substantially outweigh the potential risks of such serious adverse effects due to their rarity.