Physical urticaria: Clinical features, pathogenesis, diagnostic work-up, and management.

Physical urticaria is a type of urticaria in which recurrent wheals and/or angioedema occur following exposure of the skin to a physical stimulus. It is classified according to its triggers, which may be mechanical (friction, pressure, and vibration), thermal (cold and heat), or solar electromagnetic radiation. Symptoms of different physical urticarias can develop following specific activities that expose patients to an eliciting stimulus and may be variably accompanied by mucosal involvement and systemic symptoms, including nausea, headache, or even anaphylaxis. Differentiation of physical urticaria from other chronic urticarias requires careful clinical assessment and confirmatory provocation testing, which in turn can inform appropriate management. This clinical review provides an evidence-based summary of the epidemiology, clinical features, pathogenesis, diagnostic work-up, and management of physical urticaria.