Role of environmental conditions in urticaria. THEY ARE IMPORTANT!

Published online: November 9, 2016

Urticaria (hives) comprises a heterogeneous group of diseases that are common in the general population and have a major impact on quality of life. In most patients with urticaria, hives occur spontaneously (chronic spontaneous urticaria), but many patients identify physical triggers like water, cold, skin friction, exercise and skin pressure.  Avoidance of a suspected trigger affects their quality of life, and confirming the suspected trigger is important to avoid unnecessary lifestyle changes.

In a recent article published in The Journal of Allergy and Clinical Immunology: In Practice, Sánchez and colleagues investigated the frequency of inducible urticaria in Columbian patients with spontaneous urticaria; 245 patients with chronic spontaneous urticaria and a control group of 127 subjects without history of urticaria were recruited. Patients were questioned about triggers associated with exacerbation of urticaria, and challenge tests were performed for skin friction, pressure, cold, water, and exercise in all patients and control subjects.

A high number of patients with spontaneous urticaria reported a physical trigger (75.9%) but only 36.3% had a positive challenge test result. The most frequent inducible urticaria according to challenge tests was skin friction (24.8%) followed by cold (13.4%), pressure (7.3%), and exercise (2%). These results demonstrated that inducible triggers are important for urticaria exacerbations but are present less frequently those patients believe.  The authors also demonstrated that environmental conditions influence the different types of inducible urticaria; People living in Medellín with mild weather had a higher frequency of symptomatic dermographism and cold urticaria than people living in Bogotá with a cold weather.

In summary, physical triggers should be verified by challenge tests to avoid unnecessary lifestyle restrictions and environmental factors such as geographical characteristics could play a key role in the development of some types of inducible urticaria.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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