Threshold values of grass pollen (Poaceae) concentrations and increase in emergency department visits, hospital admissions, drug consumption and allergic symptoms in patients with allergic rhinitis: a systematic review

Jana Becker, Nadine Steckling‐Muschack, Isabella Mittermeier, Karl‐Christian Bergmann, Stephan Böse‐O’Reilly, Jeroen Buters, Athanasios Damialis, Katharina Heigl, Joachim Heinrich, Michael Kabesch, Hanna Mertes, Dennis Nowak, Paul Schutzmeier, Sandra Walser‐Reichenbach, Alisa Weinberger, Christine Korbely, Caroline Herr, Stefanie Heinze, Susanne Kutzora