Watermelon and ragweed share allergens. Enberg RN, Leickly FE, McCullough J , Bailey J, Ownby DR. A biotin-avidin amplified ELISA was used to measure. Feb 12, Watermelon allergy is an immunologically mediated hypersensitivity reaction. Allergic reactions to watermelon are rare, but it is possible. Int Arch Allergy Immunol. ;(4) doi: / Epub Mar Identification of major allergens in watermelon. Pastor C(1).