Dissociation between history and challenge in patients with physical urticaria

• Published in: The journal of allergy and clinical immunology in practice (Cambridge, MA) Vol. 2; no. 6; p. 786
• Main Authors: Komarow, Hirsh D, Arceo, Sarah, Young, Michael, Nelson, Celeste, Metcalfe, Dean D
• Format: Journal Article
• Language: English
• Published: United States 01.11.2014
• Subjects: Adolescent; Adult; Aged; Child; Child, Preschool; Chronic Disease; Cold Temperature; Exercise Test; Female; Humans; Male; Middle Aged; Photic Stimulation; Physical Stimulation; Predictive Value of Tests; Pressure; Prognosis; Risk Factors; Risk Reduction Behavior; Severity of Illness Index; Time Factors; Ultraviolet Rays; Urticaria - diagnosis; Urticaria - etiology; Urticaria - therapy; Young Adult; Cold; Physical urticaria; Challenge testing; Dermatographism; Urticaria; Delayed pressure; Cholinergic
• ISSN: 2213-2201
• DOI: 10.1016/j.jaip.2014.07.008

Physical urticaria is a subtype of chronic urticaria induced by a physical stimulus. To evaluate the consistency between a history of physical urticaria and results of challenge testing. Seventy-six subjects, ages 3 to 77 years old, were referred with the diagnosis of a physical urticaria and were evaluated by using challenge testing directed toward the presenting diagnosis, yet included other stimuli based on history. The majority of subjects were tested to 3 or more stimuli, thus 294 provocation tests were performed. Fifty-seven subjects were surveyed for the status of their physical urticaria at least 1 year after initial evaluation. Of the 76 subjects with a positive history of a physical urticaria, 38% (n = 29) were challenge negative to the presenting diagnosis. Eight subjects within the challenge negative group reacted positively to additional testing, thus 28% (n = 21) remained negative to all challenge testing, which allowed discontinuation of medications and avoidance behavior. A negative challenge result was less likely with subjects who presented with cold-induced urticaria (25%), delayed pressure urticaria (25%), and dermatographism (29%), yet more common with cholinergic (65%) and solar urticaria (67%). A 1-year follow-up survey of 57 subjects was consistent with initial results. Nineteen of this subgroup were rechallenged for the presenting diagnosis, and the outcome was unchanged in 17 subjects and, in 2 subjects the urticaria had resolved. The diagnosis by history of a physical urticaria should be verified by testing whenever possible and particularly if the condition is judged as severe and thus requires both significant life-style changes and pharmacologic intervention.