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), and other rare type; 1) and 2) include SAT based on pathogenesis. There have been no studies on differences in the prevalence of bronchial asthma among the CholU subtypes. This is investigated in the present study by evaluating the bronchial responsiveness of each subtype.
Methods
Patients 16–80 years of age with CholU were enrolled. We analyzed bronchial responsiveness, respiratory symptoms, and exhaled nitric oxide (FeNO). Bronchial responsiveness was assessed using the methacholine dose indicator Dmin.
Results
A total of 11 patients with conventional SAT-CholU, 11 with CholU-PA, and 11 with CholU-Anhd were enrolled. Median log10 Dmin (interquartile range) of patients with conventional SAT-CholU, CholU-PA, and CholU-Anhd was 0.381 (−0.829, 1.079), 0.717 (0.249, 0.787), and 1.318 (0.121, 1.699), respectively (p=0.516). Dmin was lower in patients with SAT (conventional SAT-CholU and CholU-PA) than in those with CholU-Anhd, although the differences among the 3 types were not significant. 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). One of 11 conventional SAT-CholU patients (9.1%) and 6 of 11 CholU-PA patients (54.5%) required treatment for bronchial asthma.
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.
Trial registration number
UMIN 000025669; https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000027550