Post-Vaccination Myositis and Myocarditis in a Previously Healthy Male

Abstract

Rhabdomyolysis is the breakdown of muscle cells leading to the release of cellular constituents such as electrolytes, enzymes and myoglobin. There is a broad differential diagnosis for this condition. In this report we describe a 65 year old male who presented with weakness, rhabdomyolysis, and acute kidney injury five days after receiving the seasonal flu vaccine. Laboratory investigations showed elevated creatine kinase and troponin-I, and extensive cardiac investigations yielded a diagnosis of myocarditis. The cause of his clinical picture is explored in this case report. Case PresentationA 65 year old previously healthy male presented to hospital with profound weakness. Five days before admission he had received the seasonal influenza vaccine, comprised of one influenza A H1/N1 virus, one influenza A H3/N2 virus and one influenza B virus. Two days later, he developed bilateral crampy leg pain, muscle tenderness and weakness that progressed until the day of admission. He became unable to weight-bear and was brought to the emergency department by his wife. He denied symptoms of headaches, paresthesias, arthralgias or any new rash. An infectious review of systems was unremarkable and he did not have any constitutional symptoms. He was not taking any medications or herbal preparations prior to admission, and did not use recreational drugs.On physical exam his vitals were: P 92, BP 124/84, RR 20, T 36.7°C and his O 2 saturation was 100% on room air. His neurological exam was significant for 4/5 strength in the hip flexors, hip extensors, hip abductors and hip adductors. He could not stand from the sitting position without the aid of his arms. The muscles of his arms and legs were also tender. His cardiac examination revealed a jugular venous pressure (JVP) two cm above the sternal angle. His apical beat was normal. Auscultation revealed a normal S1 and S2 without any extra sounds, murmurs or rubs. His respiratory exam revealed mild crackles in the left lower lung zone. The rest of the examination was unremarkable.His blood counts were WBC 11 × 99/L, hemoglobin 123 g/L (MCV 83 fL) and platelets 134 × 109/L. Electrolytes included sodium 126 mmol/L, potassium 3.2 mmol/L, chloride 101 mmol/L, bicarbonate 17 mmol/L, phosphate 0.75 mmol/L and magnesium 0.97 mmol/L. Other investigations showed urea 11.6 mM/L, creatinine 157 mM/L, creatine kinase (CK) 7,736 U/L (normal <150 U/L) and troponin 9.44 g/L (normal <0.2 g/L). His ethanol level was negative. His EKG was normal sinus rhythm with a right bundle branch block, without ischemic features. A chest X-ray and contrast enhanced computed tomography scan of the chest revealed a hiatus hernia, a left lower lobe consolidation, and no evidence of pulmonary embolism (Figure 1).Acute rhabdomyolysis was diagnosed and the patient received four liters of fluid over the ensuing 24 hours. During volume resuscitation he developed pulmonary crackles, his JVP increased to 5 cm above the sternal angle and his O 2 saturation decreased to 90% on room air. He was placed on supplemen...