Prevalence of avocado allergy among atopic patients.

A 41-year-old woman with known food allergy to avocado was treated for anaphylaxis after eating a meal containing avocado. This prompted a study to determine the prevalence of avocado induced symptoms and skin reactivity in a group of atopic patients. One hundred consecutive atopic patients with allergic rhinitis undergoing skin testing before initiation of immunotherapy were also prick skin tested to avocado. Patients with symptoms upon avocado ingestion were also assessed for specific serum IgE antibodies to avocado. Of the 100 atopic patients not selected for avocado sensitivity, 21 had positive prick skin tests to avocado. Eight of the 21 avocado skin test positive patients reported that symptoms repeatedly followed the ingestion of avocado; two reported systemic reactions, but six noted oral symptoms only. Serum IgE antibodies to avocado were elevated in seven of the eight patients reporting symptoms after eating avocado. Seven of the eight patients also reported oral symptoms following cantaloupe ingestion. Four reported similar symptoms upon eating banana. Avocado-induced symptoms occurred in 8% of 100 consecutive atopic allergic rhinitis patients unselected for avocado reactivity. Oral, and less frequently systemic, allergy symptoms appear to be more common among the atopic population than previously appreciated.