A 16-year old boy with a lesion of the right eye developed, during the preoperative administration of a mannitol infusion, an anaphylactoid reaction characterized by hypotension, periorbital oedema and bronchospasm. This quickly resolved following cessation of the infusion and appropriate therapeutic measures. There were no long-lasting effects. We considered mannitol the causative agent because of its temporal relationship to the reaction and our inability to seriously implicate any other medication. A history of childhood atopy may have been a predisposing factor. © 1979 Canadian Anesthesiologists.
