Polymyositis: The Comet Tail After COVID-19

Area of Science:

• Rheumatology
• Infectious Diseases
• Neurology

Background:

• Infectious agents, including SARS-CoV-2, are increasingly implicated in autoimmune disorders.
• SARS-CoV-2, initially viewed as a respiratory pathogen, is now associated with various autoimmune rheumatic conditions.
• The pathogenesis of muscle injury in COVID-19 is often attributed to autoimmune inflammatory damage or cytokine storm.

Observation:

• A 52-year-old female presented with significant muscle weakness (MRC grade 3/5), body aches, and fatigue four months post-mild COVID-19.
• Clinical presentation included proximal muscle weakness and elevated muscle enzymes.
• Diagnostic workup revealed an active myopathic process on electromyography and inflammatory myopathy on muscle biopsy.

Findings:

• The patient was diagnosed with inflammatory polymyositis secondary to COVID-19.
• Treatment with prednisolone and azathioprine led to a remarkable recovery of muscle strength to MRC grade 5/5 within four weeks.
• This case adds to the limited reports of inflammatory polymyositis post-COVID-19, particularly in developing regions.

Implications:

• This case underscores the potential for SARS-CoV-2 to induce delayed-onset autoimmune inflammatory myopathy.
• Early diagnosis and immunosuppressive therapy can lead to significant functional recovery.
• Further research is needed to elucidate the precise mechanisms linking SARS-CoV-2 to autoimmune myopathies.