Neuroleptic-induced laryngeal dystonia can mimic anaphylaxis.

OBJECTIVE: A case report of neuroleptic-induced laryngeal dystonia mimicking acute anaphylaxis is presented with a review of the literature and discussion of common diagnostic difficulties.

CLINICAL PICTURE: The patient was a 24-year-old man with recently diagnosed schizophrenia who presented twice to a general hospital with difficulty speaking within 72 hours of increasing his dose of haloperidol. On both occasions, he was treated aggressively for presumed anaphylaxis with adrenaline, antihistamines and high dose corticosteroids.

TREATMENT: The symptoms resolved with supportive medical care, withdrawal of the haloperidol and substitution of risperidone. There was no evidence of hypersensitivity on subsequent skin testing with haloperidol.

CONCLUSION: This case illustrates one of the many clinical presentations of neuroleptic-induced dystonia. While suspected anaphylaxis needs to be vigorously treated, a history of neuroleptic use and particularly of a recent dosage increase should alert clinicians to the possibility of acute laryngeal dystonia.