Anaphylactic reactions after therapeutic injection of mistletoe (Viscum album L.).

Mistletoe (Viscum album) is a plant that is semiparasitic of several trees: apple, oak, pine trees, etc. Because of the probable cytolytic action of one of the leaf's most abundant composites, in some countries mistletoe is used as a complementary medicine. Although only a few adverse reactions have been noted (cephalea, fever), cases of anaphylactic shock have been described. We present three cases of severe reaction after injection of mistletoe extract. Two of the patients had cancer. The third, whose brother had cancer, used the plant for preventive purposes. We discuss the danger of possible severe reactions due to the use of products employed in so-called alternative therapies.