Isolated left upper extremity myositis and severe rhabdomyolysis in an adult with H1N1 Influenza, a case report with literature review

Acute viral myositis is a fairly rare condition and usually seen in recovery phase of illness, especially in pediatric or geriatric population. Influenza type A, specifically H1N1 may present with generalized myositis and mild elevation of creatinine kinase in addition to usual manifestations. We would like to discuss an atypical presentation of Type A Influenza (H1N1) in a middle aged male who was never immunized for influenza, presenting with fever, vomiting, anuria and acute severe left upper extremity pain. The most interesting presentation in our patient was that, it was limited to a single extremity, unlike generalized presentation, which was previously reported, acute renal failure warranting renal replacement therapy. This case serves as a reminder for clinicians about atypical manifestations of H1N1 and its threatening metabolic complications. Hence the practitioners should be aware of this rare but possible presentation of certain strains of influenza virus. It also accentuates the importance of being immunized, reminding us of the Old but Golden Adage "Prevention is better than Cure.".