Cross-sectional study of cholinergic urticaria subtypes and bronchial hyperresponsiveness

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 analyzed bronchial responsiveness using the methacholine dose indicator D_min, respiratory symptoms, and exhaled nitric oxide (FeNO). Median log10 D_min (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 were less frequently observed in CholU-Anhd than in conventional SAT-CholU or CholU-PA. 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). Nine% of conventional SAT-CholU patients and more than half of CholU-PA patients required treatment for asthma. Log D_min tended to be lower in patients with SAT-CholU than in those with CholU-Anhd. CholU-PA might be associated with asthma.