Carnitine palmitoyltransferase II deficiency and post-COVID vaccination rhabdomyolysis.

Carnitine palmitoyltransferase II (CPT II) deficiency is a disorder affecting fatty acid oxidation. The myopathic form of the condition is the most common among adults and manifests itself with a high serum creatine kinase (CK) concentration. Triggers of very high CK concentrations include periods of fasting, infection, exercise, stress, and exposure to extreme temperatures. A 27-year-old man known to have CPT II deficiency presented feeling generally unwell after his COVID-19 vaccine. His CK concentration of 105,000 U/L and deranged liver function tests (ALT 300 U/L and AST 1496 U/L) were in keeping with rhabdomyolysis. His biochemical parameters and myopathy resolved with continuous intravenous dextrose 10% and a high carbohydrate diet. Caution should be exercised when administering vaccinations (including the COVID-19 vaccination) to this population. Clinicians should be wary for signs and symptoms of CPT II deficiency exacerbations and be vigilant in monitoring serum CK.