Melon and banana sensitivity coincident with ragweed pollinosis

Abstract

Because of a suspected relationship between ragweed pollinosis and melon or banana sensitivity, 2,067 consecutive patients in an allergy practice were queried with regard to symptoms from melon or banana ingestion. Of 1,447 patients with pollinosis, 90 complained of oral pruritus, which was by far the most common symptom caused by these fruits. No melon- or banana-induced oral pruritus occurred in any of 620 allergic patients who did not have pollinosis. Melon- or banana-sensitive patients as a group showed the following characteristics: (1) All were sensitive to ragweed or grass pollen clinically and by skin test. (2) Most showed a much higher degree of skin test sensitivity to ragweed than a control group of patients with ragweed pollinosis who were not melon or banana sensitive. (3) The prevalence of asthma was much higher in the melon- and banana-sensitive group (78 per cent) than that in the control group (47 per cent). Immunologic studies with rabbit antisera showed no common antigens by Ouchterlony gel diffusion between ragweed, melon, and banana or between timothy, melon, and banana, although common antigens were found between all of the melons, (watermelon, cantaloupe, and honeydew). Passive cutaneous anaphylaxis in guinea pigs demonstrated a strong cross-reaction between ragweed antigen and cantaloupe antibody, suggesting common antigenic determinants as an explanation for the melon sensitivity-ragweed pollinosis syndrome. Possible alternative causes of this relationship are discussed.