Severe upper airway obstruction in essential tremor presenting as asthma.

A 57 year old man with essential tremor (ET) presented with a 2 year history of paroxysmal attacks of dyspnoea and wheezing. He had been diagnosed as having bronchial asthma, and propanolol was excluded from his treatment. Flow-volume loops showed abrupt changes in maximum flows, with poor reproducibility. A diagnosis of functional upper airway obstruction was confirmed by fibreoptic bronchoscopy. The importance of establishing the precise diagnosis, in order to provide appropriate treatment, is emphasized.