Dragon Fruit Allergy With Cross-Reactivity to Salsola kali and Peach.

Dragon fruit, also known as pitahaya, has become increasingly popular in Europe and the United States owing to its nutritional value and potential health-promoting properties. This study describes a patient with anaphylaxis after the ingestion of dragon fruit. We present the case of a patient who experienced a systemic reaction requiring hospitalization 1 h after consuming dragon fruit. His medical history includes allergic rhinitis to Salsola kali pollen. The diagnostic worked-up included prick-by-prick testing with fruits, skin prick testing with aeroallergens, and measurement of specific IgE using ImmunoCAP and ISAC. These tests confirmed sensitization to dragon fruit, several pollens including S. kali, and peach allergens. A protein extract was prepared from dragon fruit pulp. In the protein profile, the most intense bands were observed at 9, 26, and 54 kDa. The patient's IgE recognized multiple bands ranging from 16 to >100 kDa. Immunoblot inhibition demonstrated cross-reactivity: S. kali extract almost completely inhibited IgE recognition of dragon fruit proteins, leaving only faint recognition of a 54-kDa band (identified as catalase), while peach peel extract completely inhibited IgE binding to the dragon fruit extract. In conclusion, sensitization to dragon fruit in this patient was probably due to cross-reactivity with S. kali and peach allergens. This case highlights the potential risks associated with the introduction of novel foods into the diet, particularly in patients previously sensitized to pollen or other plant-derived foods.