INTRODUCTION & OBJECTIVES: Chronic urticaria is associated with recurrent episodes of itchy hives. Research often focus on chronic spontaneous urticaria, whereas little is known about the patient experience of chronic inducible urticaria (CIndU). The aim of this analysis was to explore patient-reported symptom burden associated with CIndU using baseline data from a phase 3 clinical trial.
MATERIALS & METHODS: Exploratory analysis was conducted using baseline data from 39 patients diagnosed with CIndU (symptomatic dermographism [SDerm], cholinergic urticaria [CholU], cold urticaria [ColdU]). Patients completed the newly developed Urticaria Symptom Daily Diary (USDD) over 7 days prior to baseline, as well as the Dermatology Life Quality Index (DLQI/Children’s DLQI [CDLQI]) and a Patient Global Impression of Severity item (PGIS) at baseline. The USDD collects information on trigger exposure and avoidance, and severity of symptoms (itch, burning, pain, hives) on 0-10 scales. On day 1 of completion, patients indicated whether itch, burning or pain was their most bothersome symptom (MBS). A 7-day score for each symptom (ISS7, BSS7, PSS7, HSS7) was computed as the average of daily scores on trigger-exposure days. The most severe symptom (MSS) was defined as the highest of ISS7, BSS7 and PSS7. Analyses included descriptive statistics, analysis of variance and correlations.
RESULTS: The sample comprised 39 patients: 17 SDerm, 12 CholU, 10 ColdU (mean age 31.8 [SD 13.5, range 12-63]; 51% male). Patients reported trying to avoid triggers on an average of 3.9 days over the 7 days; however, out of 153 attempted trigger-avoidance days across the sample, 71% still resulted in trigger exposure. Patients were exposed to triggers on an average of 3.9 days over the 7 days and experienced symptoms on 86% of trigger-exposure days. Itch was most often the MBS (69%), followed by burning (15%) and pain (5%); patients with CholU were more likely to select burning or pain. Of the 30 patients who reported an MBS and had 7-day scores available, the MBS was also the MSS for 70% of them. Patients with CholU and ColdU were more likely to have different MBS and MSS than those with SDerm. 7-day scores were highest for itch (ISS7) and lowest for pain (PSS7); all scores worsened with increased PGIS (Table 1). Correlations between DLQI/CDLQI and 7-day symptom scores ranged from 0.54 (PSS7) to 0.66 (ISS7).
CONCLUSION: This analysis suggests that avoidance of trigger exposure is not always possible. Within this small sample, itch was frequently the most severe and the most bothersome symptom. Nonetheless, burning was an important symptom for some patients, particularly those with CholU and ColdU. Consideration needs to be given to trigger avoidance and wider symptom experience when assessing patient-centered outcomes in CINDU. Approaches such as the most bothersome symptom have the potential to further enhance the patient relevance of patient-centered outcomes.
