title: Allergic reaction to cyanocobalamin injection.
mesh_terms: D000368:Aged; D004342:Drug Hypersensitivity / Q000209:etiology*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D014805:Vitamin B 12