Background: Aniseed is a spice frequently used in Mediterranean cooking and, as with other Umbelliferae, it has been involved in clinical allergy.
Objective: This investigation was undertaken to study the allergens implicated in a case of occupational allergy to aniseed associated with rhinoconjunctivitis and gastrointestinal symptoms.
Methods: Skin prick tests were performed to inhalant allergens, spices used in the patient's workplace (aniseed and cinnamon), and 12 other Umbelliferae spices, birch, and mugwort. A nasal challenge test to aniseed and cinnamon and a double-blind placebo-controlled oral food challenge test to aniseed were also performed. The molecular weights of the allergens were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblotting and cross-reactivity among Umbelliferae species by enzyme immunoassay inhibition.
Results: Skin prick tests showed a positive immediate response to aniseed, asparagus, caraway, coriander, cumin, dill, and fennel extracts, and an intense late response to aniseed. Skin prick tests to celery, carrot, birch pollen, and mugwort pollen extracts were negative. Results of a nasal challenge test were positive to aniseed and negative to cinnamon; an aniseed oral food challenge test yielded a positive response. The molecular weights of the main immunoglobulin (Ig)E-binding proteins in aniseed extracts were approximately 48, 42, 39, 37, 34, 33, and 20 kD. Caraway, fennel, cumin, and coriander extracts showed similar IgE-binding patterns. Enzyme immunoassay inhibition studies with the patient's serum revealed cross-reactivity among the IgE components from aniseed, caraway, coriander, fennel, and dill extracts.
Conclusions: We demonstrate the presence of aniseed allergens in a case of occupational rhinoconjunctivitis and food allergy, with molecular weights for this spice that differed from those previously reported.