Necrotising myositis presenting as multiple limb myalgia
A previously healthy 40-year-old man was referred by his general practitioner to our hospital after a short prodromal period of a sore throat and rapidly deteriorating constitutional symptoms. Most pertinent to his diagnosis was the development of non-traumatic, localised, right calf pain 48 hours before admission that progressed to an inability to bear weight by the time of hospital presentation. On initial physical examination, he had a temperature of 37.8°C, diffuse muscle tenderness in all four limbs and an exquisitely hyperalgesic localised area on the right mid-calf. Examination of his throat showed a diffuse pharyngitis. There was no rash or arthritis, and his cardiovascular, respiratory and gastrointestinal systems were all unremarkable at admission.
A blood sample and throat swab were taken and, after an initial blood and microbiological culture work-up, empirical treatment with intravenous flucloxacillin and vancomycin was commenced. Early pathology test results showed a creatine kinase (CK) level of 380 U/L (reference interval [RI], < 171 U/L), serum creatinine level of 158 μmol/L (RI, 55–105 μmol/L), white cell count of 3.1 × 109/L (RI, 4.0–11.0 × 109/L) with increased band forms, and deranged liver function test results, with a bilirubin level of 60 μmol/L (RI, < 20 μmol/L) and alanine…