Occupational IgE‐mediated asthma, rhinoconjunctivitis, and contact urticaria caused by Easter lily (Lilium longiflorum) and tulip

Background: We report on IgE‐mediated asthma, rhinoconjunctivitis, and contact urticaria to two Liliaceae plants, tulip and Easter lily (Lilium longiflorum), diagnosed in a floral shop worker. Methods: Occupational asthma was diagnosed according to patient history, PEF monitoring, and a work‐simulating provocation test. Flower‐specific IgE was studied, and RAST inhibition tests were performed. Results: Skin prick testing showed positive reactions to tulip, Easter lily, and chrysanthemum. Total IgE was 180 kU/l, and specific IgE to tulip was 2.6 and to Easter lily 6.5 kU/l. In the RAST‐inhibition test, no cross‐reactivity was found. Occupational asthma was diagnosed by peak flow monitoring at work and at home, as well as specific inhalation challenge with Easter lily, with an immediate 18% reduction in PEF. In addition, contact urticaria and conjunctivitis were diagnosed. After a 9‐year follow‐up without exposure to lilies, the skin prick tests to L. longiflorum and tulip were still positive, but the specific IgE had disappeared. Conclusions: A case of IgE‐mediated occupational asthma, rhinoconjunctivitis, and contact urticaria caused by L. longiflorum and tulip is presented. RAST inhibition tests indicated concomitant sensitization to the two Liliaceae plants.