Increased Mortality Seen Among Patients With Concomitant AD, Asthma

Researchers assess mortality rates among those with just asthma, just atopic dermatitis, and individuals with both conditions in Denmark.

Adults with concomitant asthma and atopic dermatitis (AD) have an increased risk of death compared with those with asthma alone, while adults with AD, asthma, or both conditions have an increased risk of death overall, according to research published in Clinical and Experimental Allergy.

“Overwhelming evidence supports a causal link between occurrence of asthma and AD,” authors wrote, and “the prevalence of asthma among patients with AD is reported to be as high as 25%.”

Despite ample research on the significant association between asthma and AD, data on excess mortality in these patients have yet to be investigated. To determine the mortality rate in patients with hospital-diagnosed concomitant AD and asthma, those with just AD, patients with just asthma, and the population without these diseases, investigators carried out a nationwide registry-based study. Authors also looked into the impact of health care utilization on AD and asthma mortality rates.

Patient data were gleaned from the Danish National Patient Registry and the National Causes of Death Registry. Other demographic and medicinal information were collected from additional administrative registries.

Participants included Danes aged 18 years or older included in registers from 1997. AD was defined as 2 hospital diagnoses of AD with an interval of at least 6 months between each one. Asthma was defined as a diagnosis of the condition, in addition to at least 2 filled prescriptions for inhaled corticosteroids, authors explained.

Individuals were followed until migration, death or December 2018, and “subjects with AD were individually age (at index) and sex-matched with the background population of individuals without a diagnosis of AD in a 1:4 ratio.”

Of the 8095 individuals included who had AD, the majority (61.8%) were women. Of these, 1201 (14.8%) had concomitant asthma. A total of 32,380 reference individuals who did not have AD were also included in analyses; of these 878 (2.7%) had asthma.

Analyses revealed:

  • A total of 1057; 330; 55; and 99 deaths were observed among subjects with neither AD nor asthma, AD only, asthma only, and subjects with concomitant AD and asthma, respectively
  • The mortality rate per 1000 person-years was 4.75 (95% confidence interval [CI], 4.47–5.05) for subjects with neither AD nor asthma, 7.17 (95% CI, 5.92–10.05) for asthma only, 7.09 (95% CI, 6.37–7.90) for AD only and 10.87 (95% CI, 8.92–13.23) for concomitant AD and asthma
  • Risk for all-cause mortality was increased in subjects with concomitant AD and asthma compared to asthma only (hazard ratio [HR] 1.52; 95% CI, 1.07–2.15) and neither AD nor asthma (HR 2.27; 95% CI, 1.83–2.81) but not compared with subjects with AD only (HR 1.10; 95% CI, 0.87–1.39)
  • Compared with AD only, subjects with AD and asthma had increased risk of death due to pulmonary disease (HR 1.81, 95% CI 1.04–3.15)

Mean age at death was highest in subjects with neither AD nor asthma (73.32 years) compared with subjects with AD only (69.28 years), concomitant AD and asthma (69.61 years), and asthma only (72.07 years)

Researchers also found hospital admission for asthma and asthma-related emergency department visits and hospital admission for AD were all significant predictors of death for those with both conditions.

“Men had increased risk of death in all 4 groups, though not statistically significant for subjects with asthma only. The results are in line with previous literature, showing that men have higher mortality compared with women,” authors wrote.

Data also revealed increased death due to psychiatric diseases for patients with both conditions. According to researchers, increased focus on diagnosing and managing asthma in patients with AD is warranted.

“Early intensive patient education and written action plans, including early use of oral corticosteroids at home, are the key components to decrease emergency room visits and hospitalizations for asthma,” they said.

Adults with these conditions treated by a general practitioner or in a private clinic were not included in the present analysis, marking a limitation to the study. Information on body mass index, smoking and alcohol consumption was also not available.

“Future studies should investigate whether asthma is more severe in patients with concomitant AD and asthma compared to asthma only,” the researchers concluded.


Ali Z, Ulrik CS, Egeberg A, Thyssen JP, Thomsen SF. Increased all-cause mortality in concomitant atopic dermatitis and asthma: a nationwide registry-based study. Clin Exp Allergy. Published online June 30, 2021. doi:10.1111/cea.13978