Seronegative Erosive Arthritis Following SARS-CoV-2 Infection.

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affecting mostly the respiratory system, but several other organs and systems can be involved. Extrapulmonary manifestations and autoimmune phenomena following SARS-CoV-2 infection are frequent events occurring during the first 2 weeks or in later stages of the disease course. These can be expressed as an isolated discovery of autoantibodies, mostly antinuclear or antiphospholipid antibodies, through to full-blown autoimmune organ-specific and systemic diseases. Joint pain is a frequent complain in most patients, but to our knowledge, frank arthritis has not been reported so far. A 46-year-old woman developed symmetrical polyarthritis 2 months after SARS-CoV-2 infection. Laboratory tests showed high acute phase reactants, while the immunological profile was negative. Hand and wrists X-rays revealed soft tissue swelling as well as bone erosions at the ulnar base of the third and fourth metacarpophalangeal joint of the right hand and carpal bones. The patient responded well to small doses of prednisone and methotrexate and after 4 months she had a sustained clinical and laboratory improvement. This is the first report making an association between SARS-CoV-2 infection and erosive polyarthritis. Physicians dealing with patients infected from SARS-CoV-2 should be aware for the possible development of musculoskeletal disorders, among them symmetrical polyarthritis. Thus, a close follow-up and monitoring is mandatory.