Bee pollen-induced anaphylactic reaction in an unknowingly sensitized subject

Background: The food supplement bee pollen has been previously found to cause anaphylactic reactions. It has been proposed as useful for "everything from bronchitis to hemorrhoids." Objective: This study describes an atopic patient who experienced a non-life-threatening anaphylactic reaction upon her initial ingestion of bee pollen. Microscopic examination of the pollen sample and ELISA inhibition assays were performed. Results: The patient had a 7 mm/28 mm wheal/erythema reaction to bee pollen at 1 mg/mL concentration. Bee pollen caused 52% inhibition of IgE binding to short ragweed and 55% to ryegrass. Microscopic analysis revealed ragweed, Alternaria, Cladosporium, honeysuckle (Lonicera sp), privet shrub (Ligustrum sp), and vetch (Vicia sativa). Conclusions: An unknowingly sensitized atopic patient experienced an anaphylactic reaction after ingestion of a small quantity of bee pollen that contained pollens and fungi. Previously administered allergen immunotherapy that had reduced rhinitis symptoms did not prevent this allergic reaction.