Clinical characteristics and severity of concomitant atopic dermatitis in adults with asthma: a nationwide population-based registry study

Background Atopic dermatitis (AD) often coexists with asthma, but the characteristics of AD in adults with asthma are largely unknown. Objective The objective of this work was to examine the characteristics and severity of AD in adults with asthma. Methods This population-based registry study identified adults (18–45 years) with an inpatient or outpatient asthma diagnosis in Danish hospitals between 1 January 2000 and 31 December 2019. AD history was determined by inpatient or outpatient diagnostic codes. AD and asthma severity were assessed through patient surveys using the Patient-Oriented SCORing Atopic Dermatitis (PO-SCORAD) and the Global Initiative for Asthma (GINA) 2024. Results Among 4,126 patients (15% response rate), 5.2% had AD. Of these, 22.7% were treated with GINA Step 4–5. Patients with AD were primarily women (74.3%) with childhood-onset AD (90.7%) and asthma (82.6%, p < 0.001). Mean (standard deviation) PO-SCORAD was 25.4 (16.1)). Asthma severity was not correlated or associated with AD severity. AD involvement in the head-and-neck region and on hands was common (54.0%; 61.3%) and associated with higher PO-SCORAD scores ( p < 0.05; p < 0.001). AD flares during asthma exacerbations were reported by 33.0% of patients ( p < 0.001). Conclusions Asthma patients with AD often have childhood onset of both conditions and mild-to-moderate AD. Clinicians should recognize that AD in high-burden skin areas is common in asthma patients.