Researchers Report First-Known Case of COVID-19–Triggered Psoriatic Arthritis

Doctors in Italy reported what is believed to be the first known case of psoriatic arthritis triggered by coronavirus disease 2019 (COVID-19).

Although the mechanisms triggering autoimmune/autoinflammatory attacks remain unknown, SARS-CoV-2 —the virus which causes COVID-19 —has been shown to result in a wide variety of these disorders, including cytokine storm/macrophage activation syndrome (MAS), diseases affecting the blood vessels, anemia, clotting issues, skin conditions, and demyelination syndromes including Guillan–Barrè syndrome, according to the report published in Rheumatology.

A small number of arthritis cases reportedly tied to SARS-CoV-2 infections fall into 3 groups possibly associated with viral infections: viral arthritis, reactive arthritis, or chronic arthritis triggered by viral infections, according to researchers.

However, doctors from Humanitas Clinical and Research Center in Milan believe they have diagnosed the apparent first case of psoriatic spondyloarthritis. The patient, a 27-year-old woman, had a genetic predisposition due a family of history of psoriasis, although no family members showed skin or nail lesions or joint-related issues.

In February 2020, the woman developed acute arthritis in her left ankle, followed 7 days later by loss of taste and smell without fever or cough, the authors noted. She was never tested for COVID-19 and symptoms resolved on their own within 2 weeks.

In May, however, she developed left knee arthritis and a skin lesion on her lower back resembling psoriasis, the authors said. Her inflammatory markers were slightly elevated, although other indicators of arthritis or inflammatory disease, such as rheumatoid factor, anticitrullinated peptides, and anti-nucleus antibodies, were negative.

Two months later in July, the woman was admitted to the hospital for diarrhea, low back pain, and arthritis in the left knee and the metatarsophalangeal joints, according to the report. At that point, she was tested for SARS-CoV-2 via a nasal swab, which turned up negative, but did test positive for antibodies. Synovial fluid collected in May also tested negative for COVID-19 but positive for antibodies. She had no fever or respiratory symptoms, and a chest computerized tomography (CT) scan was negative for COVID-19 pneumonia. 

The authors diagnosed psoriatic spondyloarthritis triggered by SARS-CoV-2 infection in this genetically predisposed individual after excluding viral arthritis, which has an acute phase, typically resolves on its own, and was not evidenced in the synovial fluid. A diagnosis of reactive arthritis was also considered unlikely because the onset of arthritis occurred before clinical manifestation of viral infection, while reactive arthritis generally develops 1 to 24 weeks from the infection.

A virus-induced hyperinflammatory environment has been suspected as a mechanism for MAS, while a shift in Th17 cells has been hypothesized to trigger reactive arthritis. The authors wrote that previously documented cases of rheumatoid arthritis and the new case of spondyloarthritis suggest alternative mechanisms such as immune-surveillance escaping.

References

Novelli L, Motta F, Ceribelli A, et al. A case of psoriatic arthritis triggered by SARS-CoV-2 infection. Rheumatology (Oxford). Published online November 19, 2020. doi:10.1093/rheumatology/keaa691