Study aims to identify atopic dermatitis phenotypes, risk factors

Phenotype characterization and risk factors for atopic dermatitis can help patients with prevention and therapy, according to a study.

“Atopic dermatitis (AD) is the most common chronic inflammatory skin disease with a high impact on patients’ quality of life, productivity at work and burden on the health system, with an increasing cumulative lifetime prevalence of 15% to 28% in industrial nations,” Laura Maintz, MD, of the department of dermatology and allergy at University Hospital Bonn in Germany and the Christine Kühne-Center for Allergy Research and Education Davos in Switzerland, and colleagues wrote. “There is a wide range in the clinical phenotype, with severity ranging from minimal to erythrodermic forms involving the whole body and many different disease courses.”

Researchers analyzed cross-sectional data from a prospective longitudinal study of 367 patients (mean age, 39 years; 94% adults; 42.8% male) with AD. Using the Eczema Area and Severity Index, patients were categorized by severity groups and 130 AD severity factors were analyzed.

Mild AD was present in 48.2% (n = 177) of patients, 32.7% (n = 120) had moderate AD and 19.1% (n = 70) had severe AD.

Quality of life, as measured by the Dermatology Life Quality Index, was shown to be directly correlated with EASI severity, with more than 50% of those with moderate to severe AD having a highly reduced QOL.

An increased probability of severe AD was found in those with atopic stigmata, such as cheilitis (OR = 8.1; 95% CI, 3.35-10.59), white dermographism (OR = 4.42; 95% CI, 1.68-11.64), Hertoghe sign (OR = 2.75; 95% CI, 1.27-5.93) and nipple eczema (OR = 4.97; 95% CI, 1.56-15.78). Those with alopecia areata had an increased probability of moderate AD (OR = 5.23; 95% CI, 1.53-17.88) or severe AD (OR = 4.67; 95% CI, 1.01-21.56), while female sex had a lower probability of severe AD (OR = 0.3; 95% CI, 0.13-0.66).

Total serum immunoglobulin E (tIgE) levels were useful in predicting severity, according to the authors, with a higher probability of severe AD when tIgE levels were greater than 1,708 IU/mL and a higher probability of mild AD when tIgE levels were less than 467 IU/mL.

The age of AD onset also impacted severity as those who had onset in childhood were more likely to develop mild AD and those who had adolescent or early adulthood onset of AD were more likely to have stronger AD.

Those who developed AD later in life, after age 33, were more likely to have severe AD.

Patients who exhibited lifestyle factors such as lack of exercise and smoking were more likely to develop moderate or severe AD, while those who never smoked and participated in sports at least once a week were more likely to have mild AD.

“A better characterization of the phenotype might help to identify patients at risk for severe disease and facilitate early therapeutic intervention and prevention,” the authors wrote. “Moreover, we could identify concrete critical time frames regarding age and age at onset, cutoff points for tIgE levels and eosinophil values as predictive biomarkers, and several atopic stigmata associated with disease severity in this study.”