Dissociation Between History and Challenge in Patients with Physical Urticaria

Abstract

Background Physical urticaria is a subtype of chronic urticaria induced by a physical stimulus. Objective To evaluate the consistency between a history of physical urticaria and results of challenge testing. Methods Seventy-six subjects, ages 3–77, were referred with the diagnoses of a physical urticaria and were evaluated 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 one year after initial evaluation. Results Of the 76 subjects with a positive history of a physical urticaria, 38 %(N=29) were challenge negative to the presenting diagnosis. Eight patients within the challenge negative group reacted positively to additional testing, thus 28 % (N=21) remained negative to all challenge testing, allowing discontinuation of medications and avoidance behavior. A negative challenge result was less likely in subjects presenting with cold induced urticaria (25 %), delayed pressure urticaria (25 %) and dermatographism (29 %), yet more common in cholinergic (65 %) and solar urticaria (67 %). A one-year follow-up survey of 57 subjects was consistent with initial results. Nineteen of this sub-group were rechallenged for the presenting diagnosis and the outcome was unchanged in 17 patients and in two patients the urticaria had resolved. Conclusions 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.

Physical urticaria: Review on classification, triggers and management with special focus on prevalence including a meta-analysis

“…Establishing the diagnosis of PU with provocation tests is crucial given that almost a third of patients reporting history suggestive of PU may have negative challenge testing which allows discontinuation of medications and avoidance behavior [9]. The clinical characteristics, diagnostic approach and potential pathogenic mechanisms of the main forms of PU are enlisted below:…”

Prevalence of Chronic Inducible Urticaria in Elderly Patients

“…However, we did not find any discrepancy between the self-reported data and the CT results in our elderly patients. No serious adverse events were recorded during testing, which illustrates the safety of the provocation tests used to identify CIndUs, according to Komarow et al [ 21 ]. Nevertheless, it is appropriate to reiterate that CTs should be conducted in safe conditions for the eventuality, albeit very rare, of side effects.…”

“…Generally, there may be some conflicts between the self-reported symptoms of certain CIndUs and specific positive CT results [ 21 ]. However, we did not find any discrepancy between the self-reported data and the CT results in our elderly patients.…”

“…Older age is associated with structural and physiological skin changes [ 15 ]. A reduction in dermal thickness, a decrease in cutaneous vascularity and cellularity, and reduced histamine skin reactivity are observed with aging [ 18 , 21 ]. Moreover, immune function is remodeled in older age (immunosenescence) [ 22 ].…”

Self-Reported Provoking Physical Factors in Patients with Chronic Urticaria: A Questionnaire Study

“…The high frequency of cholinergic stimuli could be explained by the demographic characteristics of our study population: a few young male patients visited our clinic to obtain medical reports for military service. Previous studies reported that 44%~62% of patients with suspected CIndU were only diagnosed after further provocation tests and diagnostic work-up 4 5 6 . This discrepancy could be explained by the tendency of patients with CU to overestimate the role of their triggers 5 .…”