Resolution
Of the 52 participants, four (7.7%) participants were lost to follow-up. From study entry, patients were followed for a median of 2.6 years (IQR: 0.9, 5.6). Disease resolution was recorded in 12 (25.0%) of the remaining 48 participants over 248.0 patient-years (4.8 cases of disease resolution per 100 patient-years). Among those whose disease resolved, median age at resolution was 9.0 years (IQR: 8.0, 15.5) and median disease duration was 3.5 years (IQR: 1.0, 7.0). Of those with persistent coldU, median disease duration was 5.3 years (IQR: 2.0, 8.0).
Data on disease resolution was available in all 103 CSU patients, of which 33 (32.0%) resolved over 290 patient-years (11.4 cases of resolution per 100 patient-years). Of those experiencing CSU resolution, median disease duration and age at disease resolution were 1.4 (IQR: 0.79, 2.1) and 9.0 (IQR: 4.9, 13.7) years, respectively. Median disease duration was 2.3 years (IQR: 1.6, 4.0) in patients with persistent CSU.
When controlling for age at disease onset and sex, multivariate cox regression analysis revealed that cases of coldU were significantly less likely to experience disease resolution than cases of CSU (adjusted hazard ratio: 0.43 [95%CI: 0.21, 0.89], P<10-2, Figure 1).