Occupational IgE-mediated allergy after exposure to lupine seed flour

The ingestion of lupine seed flour (LSF) has been reported as a cause of al lergic reactions, particularly in patients sensitized to peanut, but there is little evidence of its allergenic potential after inhalation. We sought to evaluate the clinical and immunologic reactivity to lupine in employees working with this seed flour. An occupational history was obtained in 7 sub jects (median age, 35 years) working with LSF at an agricultural research c enter. Three subjects (1, 6, and 7) reported work-related allergy symptoms immediately after being exposed to lupine. Skin prick test results with LSF extract were positive in these 3 patients with work-related symptoms. More over, lupine-specific IgE antibodies were detected in subjects 6 and 7. In subject 6, the controlled exposure to LSF elicited immediate naso-ocular sy mptoms without changes in FEV1. In subject 7, a bronchial provocation with LSF extract elicited an immediate fall (25%) in FEV1. Double-blinded, place bo-controIled LSF oral challenge results were positive in subjects 6 and 7. Immunologic reactivity to other legumes was detected in subjects 6 and 7, but specific inhalation testing and oral challenge results were negative. T hus, the inhalation of lupine flour could be an important cause of allergic sensitization in exposed workers and might give rise to occupational asthm a and food allergy.