Patient-reported comorbidities with AD
In the total population, 9906 patients (60.95%) did not identify any comorbid diseases, 4717 patients (29.02%) identified as having one comorbid disease, while 1631 patients (10.03%) identified as having more than one comorbid diseases. Among patients who have identified as having at least one atopic comorbidity, allergic rhinitis had the highest prevalence, followed by food allergy, asthma, chronic urticaria, and drug allergy (Table 2). Patients having asthma and food allergy comprised a significantly higher proportion of severe AD, whereas patients with allergic rhinitis comprised a significantly higher proportion of moderate AD. Meanwhile, patients comorbid with chronic urticaria comprised a significantly higher proportion of mild AD. Remarkably, chronic urticaria (odds ratio [OR], 0.74; 95% CI: 0.63–0.87) might be protective against AD, whereas food allergies (OR, 1.21; 95% CI: 1.06–1.37, P = 0.003) might be a risk factor for AD. Among patients who were identified as having at least one non-atopic comorbidity, hypertension was the highest prevalence, followed by diabetes and coronary heart disease (Table 2). Patients with hypertension, diabetes, and coronary heart disease comprised a significantly higher proportion of severe AD compared to mild and moderate. The non-atopic comorbidities of hypertension (OR, 1.61, 95%CI: 1.35-1.93, P<0.001) and diabetes (OR, 1.64, 95%CI: 1.27-2.12, P<0.001) are potential aggravating factors for AD.