Background: Urticaria is a frequent skin condition, but reliable prevalence estimates from population studies particularly of the chronic form are scarce.The objective of this study was to systematically evaluate and summarize the prevalence of chronic urticaria by evaluating population‐based studies worldwide.

Nasal Allergen Challenge and Environmental Exposure Chamber Challenge: A Randomized Trial Comparing Clinical and Biological Responses to Cat Allergen

Allergen-specific IgE measurements and the clinical history are the cornerstones of allergy diagnosis. During the past decades, both characterization and standardization of allergen extracts and assay technology have improved. Here we discuss the uses, advantages, misinterpretations, and limitations of ImmunoCAP IgE assays (Thermo Fisher Scientific/Phadia, Uppsala, Sweden) in the field of allergology.