Budesonide and nasal histamine challenge.

The possible mode of action of the lately demonstrated steroid effect on the immediate type allergic reaction was investigated. The influence of a topical steroid, budesonide, on the effects that released mediators have on the nasal mucosa was also studied. A nasal histamine challenge study was performed in a double-blind, cross-over fashion, a 1-week pretreatment with budesonide or placebo preceding the challenge. Symptoms were recorded by means of symptom score as well as objectively via rhinomanometry. In contrast to a previous allergen challenge study, the steroid was found to have minimal effect on the histamine-induced nasal symptoms. It is therefore concluded that other modes of steroid action must also be involved in the steroid effect on the immediate type allergic reaction.