Avocado hypersensitivity.

The avocado (Av) is a fruit that belongs to the Lauraceae family. We report 17 patients with immediate hypersensitivity to avocado. Clinical manifestations in relation to avocado ingestion were as follows: systemic anaphylaxis in seven patients, angioedema/urticaria in six, vomiting in two, bronchial asthma in one, and rhinoconjunctivitis in one. Skin prick test (SPT) with fresh avocado was positive in all patients with the Strong avocado variety (SAv) and in 14 patients with the Hass avocado variety (HAv). Our patient-associated sensitizations were as follows: 10 to latex, eight to chestnut, eight to banana, four to kiwi, and four to walnut. Avocado-sensitized patients with latex allergy were typically middle-aged women, professionally exposed to latex, who also exhibited frequent associated sensitizations to chestnut, banana, and other fruits. Specific IgE against avocado was demonstrated in 11 of our patients, by both commercial CAP and RAST with avocado extract coupled to nitrocellulose disks. Despite its lower protein content, SAv seems to be more allergenic than HAv, both in vivo and in vitro. On incubating a pool of sera from our patients with avocado, latex, chestnut, and banana extracts, a progressive RAST inhibition was obtained, with SAv- and chestnut-marked disks. This suggests the existence of common antigenic determinants among these allergens.