Table 1

Clinical features and management of four patients with acute arthritis during COVID-19 admission

Patient	1	2	3	4
Age (years)/gender	71/male	61/male	64/male	45/male
Days from COVID-19 symptom onset to arthritis	8	19	8	27
Days from admission to arthritis	3	17	7	21
COVID-19 management	Hydroxychloroquine	Hydroxychloroquine, azithromycin, tocilizumab, pulses of methylprednisolone	Hydroxychloroquine, azithromycin, lopinavir–ritonavir, tocilizumab	Hydroxychloroquine, tocilizumab, pulses of methylprednisolone
Known inflammatory arthritis	Gout, on allopurinol 100 mg/day	Gout, on allopurinol 100 mg/day (irregular)	Previous recurrent arthritis, not studied or treated	Crystal-proven gout, on allopurinol 300 mg/day
Allopurinol stopped during admission	No	No	–	Yes
Involved joints	First MTP	Ankle	Both knees	Knee and ankle
SF characteristics	ND	Glucose: 38 mg/dL Leucocytes: 137 534/μL (95% PMN)	Glucose: 94 mg/dL Leucocytes: 1362/μL (77% PMN)	Glucose: 38 mg/dL Leucocytes: 39 065/μL (96% PMN)
Polarised light microscopy	MSU crystals	MSU crystals	CPP crystals	MSU crystals
SF culture	ND	Negative	Negative	Negative
SF RT-PCR for SARS-CoV-2	ND	Negative	Negative	Negative
Acute arthritis management	Intra-articular triamcinolone plus mepivacaine. Colchicine.	Oral prednisone. Colchicine.	Intra-articular triamcinolone plus mepivacaine.	Colchicine.

CPP, calcium pyrophosphate; MSU, monosodium urate; MTP, metatarsophalangeal; ND, not done (insufficient amount of fluid was obtained); PMN, polymorphonuclear; RT-PCR, reverse transcriptase PCR; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; SF, synovial fluid.