Guillain-Barré syndrome mimicking botulism in early disease course

A 42-year-old man, returning to Europe after a 2-month stay in China, reported cough and runny nose. Five days later, he developed neck discomfort and rapidly evolving weakness, spreading from his arms to the facial, bulbar and neck muscles, and then the legs. He developed dysphagia and breathlessness, and was intubated in the emergency department. Cerebrospinal fluid showed mildly elevated protein. On day 2 he had fixed dilated pupils, with absent oculocephalic reflexes, and a flaccid upper limb paralysis. MR scans of the brain and spinal cord were normal. The early features of descending weakness, bulbar involvement and fixed dilated pupils made it difficult to distinguish between Guillain-Barré syndrome and botulism, and early investigations were inconclusive. We initially gave both botulinum antitoxin and intravenous immunoglobulin, but initially delayed plasma exchange as this would have removed the botulinum antitoxin. Diagnostic testing for botulism has low sensitivity, so we urge pre-emptive treatment if it is clinically suspected.