Occupational rhinoconjunctivitis and asthma caused by chicory and oral allergy syndrome associated with bet v 1-related protein.
BACKGROUND A few cases of IgE-mediated chicory allergy with oral, cutaneous, and/or respiratory symptoms are reported. We present 4 patients with inhalant birch pollen allergy and oral allergy syndrome to chicory. IgE-binding proteins in chicory and cross-reactivity with birch pollen were studied. METHODS Chicory extract was prepared and immunoblotting was used to study IgE reactivity and cross-reactions with birch pollen. RESULTS The pattern of IgE binding to chicory was variable among the patients, with protein bands recognized at 18, 21, 40, 52 and 71 kD. Bet v 1-like proteins were detected in chicory by monoclonal antibody binding. Chicory-birch pollen cross-reactivity, as studied in 2 patients from whom enough serum was available, could be demonstrated but did not involve the Bet v 1 protein family. In one of these cases, a 51-kD protein of birch pollen was found to be responsible for cross-reactivity. CONCLUSIONS Chicory should be added to the list of foods that can cross-react with birch pollen and cause the birch pollen-associated oral allergy syndrome.