Aspirin-sensitive urticaria: provocation with a leukotriene receptor antagonist.

The diagnosis of two patients with aspirin-induced urticaria (AIU) was confirmed by oral provocation with aspirin, other non-steroidal anti-inflammatory drugs, and food additives. Low doses of a novel leukotriene (LT) receptor antagonist, ONO-1078 (ONO, Japan) induced urticaria in these patients, while the same doses of ONO-1078 did not provoke any eruptions in 10 normal healthy volunteers or five patients with aspirin-unrelated chronic urticaria. This is the first report that a selective LTD4/LTE4 receptor antagonist that is effective as an antiasthmatic agent evoked urticaria in patients with AIU. Our observation suggests that the pathogenesis of AIU depends on the stimulation of LT receptors. The accumulation of results of anti-LT therapy may provide clues to resolve the pathogenetic mechanisms of this disorder.