Title Page:Article Type: Letter to the EditorTitle: Anaphylaxis to a blood feeding leechAuthors: Carmen H. Li MSc1,2*, Maggie Jiang MD3*, Gabriele Gadermaier PhD4, Sebastian Kvist PhD5,6,7 Julia E. M. Upton MD8,9, Xiaojun Yin PhD1, Jennifer A. Hoang MSc MDS1,10, Mikhail Monteiro BSc1, Lisa Hung PhD1,10, Akash Kothari MSc1,2, Theo J. Moraes MD PhD1,9, Peter Vadas MD PhD3,10**, Thomas Eiwegger MD1,10,11,12***Co-first author**Co-senior author(1) Translational Medicine Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada(2) Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada(3) Division of Clinical Immunology and Allergy, St. Michael’s Hospital(4) Department of Biosciences and Medical Biology, Paris Lodron University Salzburg, Salzburg, Austria(5) Department of Ecology and Evolutionary Biology, University of Toronto, ON, Canada(6) Department of Invertebrate Zoology, Royal Ontario Museum, Toronto, ON, Canada(7) Swedish Museum of Natural History, Stockholm, Sweden(8) Division of Immunology and Allergy, Food Allergy and Anaphylaxis Program, The Hospital for Sick Children(9) Department of Pediatrics, University of Toronto, Toronto, ON, Canada(10) Department of Immunology, Temerty Faculty of Medicine, University of Toronto, Ontario, Toronto, Canada(11) Karl Landsteiner University of Health Sciences, Krems, Austria(12) Department of Pediatric and Adolescent Medicine, University Hospital St. Pölten, St. Pölten, AustriaCorrespondence:  Thomas Eiwegger, MDChair, Department of Pediatric and Adolescent MedicineUniversity Hospital St. PöltenDunant-Platz 1, 3100 St. Pölten, AustriaEmail: [email protected].: +43 2742-9004-11740