You might want to think twice before bringing a colorful poinsettia plant to cheer a friend during the holidays.
Poinsettia can cause severe reactions among people who have latex allergies. Because the biggest groups of such people are health care and food industry workers who are repeatedly exposed to latex gloves for infection control, you might want to reconsider what plant you bring into a hospital.
The ornamental poinsettia plant (Euphorbia pulcherrima), with its red or pink petals and deep green leaves, belongs to the same plant family as the Brazilian rubber tree from which latex is obtained.
Direct contact with the white, milky sap from a broken poinsettia leaf, or from pruning the plant, can trigger an allergic reaction within minutes. Symptoms can include rash, hives, sneezing, coughing, tightness in the throat and difficulty breathing; in rare instances, the reaction could be life-threatening.
"We're recommending caution, especially if the plants are crushed or damaged," said Dr. Peter M. Ranta, an allergist at the Medical College of Georgia in Augusta, who recently presented poinsettia allergy findings at the annual meeting of the American Academy of Allergy, Asthma and Immunology in New Orleans.
Ranta identified two allergy-producing proteins common to the Brazilian rubber tree and poinsettia plants. He also showed that 40% of people sensitive to latex produced antibodies to the poinsettia plant.
He said he's unaware of anyone who has had a severe reaction to poinsettia sap, but the potential is there, especially if the person has extreme reactions to latex.
He advises people with latex allergies to be careful about pruning ficus plants too. The popular Ficus benjamina belongs to the same allergy-inducing family as the rubber tree and poinsettia.
The poinsettia was named after Joel R. Poinsett, the first U.S. ambassador to Mexico, who took cuttings of it back to his native South Carolina in the 1820s.