The significance of hypersensitivity to nuts in patients with birch pollen allergy.

This study was performed in patients with allergic rhinitis/conjunctivitis to birch pollen to determine whether patients with additional hypersensitivity to nuts and apples differed from patients without such hypersensitivity; the determination was in terms of results of skin prick test (SPT), specific IgE antibodies (RAST), and symptoms during the pollen season. Forty-seven patients with birch pollen allergy were investigated by RAST against birch and hazel pollen and by SPT. They were treated in a randomized, double-blind, placebo-controlled study with fluticasone propionate aqueous nasal spray or placebo. The area of the SPTs was larger and the specific IgE values higher in patients with hypersensitivity to nuts and apples. These patients also had more symptoms during the pollen season. We conclude that hypersensitivity to nuts is an indication of a more severe allergy in patients with birch pollen allergic rhinitis.