Abstract
Background: Cholinergic urticaria (CholU) is classified into several subtypes: 1) conventional sweat allergy-type CholU (conventional SAT-CholU), 2) CholU with palpebral angioedema (CholU-PA), 3) CholU with acquired anhidrosis and/or hypohidrosis (CholU-Anhd); 1) and 2) include SAT based on pathogenesis. There have been no studies on differences in the prevalence of bronchial asthma among the subtypes. We evaluated the bronchial responsiveness of each subtype. Methods: We analyzed bronchial responsiveness using the methacholine dose indicator Dmin, respiratory symptoms, and exhaled nitric oxide (FeNO). Results: Median log10 Dmin (interquartile range) of patients with conventional SAT-CholU (n=11), CholU-PA (n=11), and CholU-Anhd (n=11) was 0.381 (−0.829, 1.079), 0.717 (0.249, 0.787), and 1.318 (0.121, 1.699), respectively (p=0.516). Respiratory symptoms evaluated using the International Primary Care Airways Group questionnaire were less frequently observed in CholU-Anhd (0 [0, 1]) than in conventional SAT-CholU (1 [0–2]) or CholU-PA (1 [1–3]) (p=0.049). FeNO of patients with conventional SAT-CholU, CholU-PA, and CholU-Anhd was 23 (18.5, 65.0), 39 (32.0, 59.5), and 25 (19.0, 33.0) ppb, respectively (p=0.237). Conclusions: Log Dmin tended to be lower in patients with SAT-CholU than in those with CholU-Anhd. Distinguishing between CholU subtypes may reveal different degrees of bronchial responsiveness based on a distinct pathogenesis.