A case report of monoarthritis in a COVID-19 patient and literature review: Simple actions for complex times.

RATIONALE: COVID-19 presentation is multifaceted and up to 44% of patients affected by COVID-19 experience musculoskeletal complaints, mostly in the form of diffuse aspecific arthromyalgias. Nevertheless, only a few cases of arthritis following SARS-CoV2 infection are reported.

PATIENT CONCERNS: A 27-year-old man affected by nail psoriasis presented with monoarthritis 2 weeks after being diagnosed with COVID-19.

DIAGNOSES: Diagnostic work-up and differential diagnosis were made difficult by patient isolation, absence of lab tests, and his visit via telemedicine, even though signs of first metacarpophalangeal joint involvement were clear.

INTERVENTIONS: Due to the inefficacy of acetaminophen and nonsteroidal anti-inflammatory drugs, the patient was prescribed oral steroids with a rapid benefit.

OUTCOMES: The patient's response to oral steroid was prompt and maintained even after therapy tapering. Even so, a formal diagnosis was not possible due to a difficult diagnostic work-up and lack of a long-term follow-up.

LESSONS: Like many other viral diseases, SARS-CoV2 can play as a causative agent or as a trigger for inflammatory arthritis development in predisposed individuals.