Discovery: The Riddle of Red-Eyes and Runny-Noses

Dr Adam Rutherford and Dr Hannah Fry investigate why things like pet hair, peanuts and pollen can get people's immune systems so riled up. Professor Judith Holloway from the University of Southampton guides the duo through the complex immune pathways that make allergies happen and tells the scary story of when she went into anaphylactic shock from a rogue chocolate bar