Atopic eczema associated with lymphopenia, regardless of immunosuppressive drug use: Study

Lymphocyte skin homing may induce lymphopenia in patients with atopic eczema. Sinéad M. Langan, London School of Hygiene and Tropical Medicine, London, United Kingdom, and colleagues determine if atopic eczema is associated with lymphopenia.

The researchers used UK primary care electronic health records for a matched cohort study in adults with at least one recorded lymphocyte count. They matched people with AE to up to five people without. Multivariable logistic regression was used to determine the association between atopic eczema and lymphopenia (two low counts of lymphocytes within three months).

The effect of lymphopenia on common infections was investigated using Cox proportional hazard models. Linear mixed-effects regression was used to estimate the association with absolute lymphocyte counts using all counts available. The study was replicated using data from a US survey [NHANES (National Health and Nutrition Examination Survey)].

The study led to the following findings:

· Among 71,731 adults with AE and 126,349 adults without AE, the adjusted odds ratio (OR) for lymphopenia was found to be 1.16, and the strength of association increased with increasing severity of eczema.

· A lower mean lymphocyte (adjusted mean difference -0.047*109/L) was seen in those with AE on comparing all recorded lymphocyte counts from people with atopic eczema (n=1,497,306) to those of people without AE(n=4,035,870).

· The difference was larger for men, increasing AE severity, increasing age, and was present among people with AE not treated with immunosuppressive drugs. In NHANES (n=22,624), the adjusted OR for lymphopenia in adults with AE was 1.30, and the adjusted mean lymphocyte count difference was -0.03*109/L.

· Despite having a lower lymphocyte count, adjusting for time with lymphopenia did not alter risk estimates of infections.

"Atopic eczema, including increasing AE severity, is linked with a decreasing lymphocyte count, irrespective of immunosuppressive drug use," the researchers wrote in their study.

"Whether the decreasing lymphocyte count has wider health implications for people with severe eczema warrants further investigation."

About Atopic Eczema

Atopic dermatitis or eczema is a condition that leads to itchy, dry and inflamed skin; it commonly occurs in young children but can occur at any age. The disorder is chronic or long-lasting and sometimes tends to flare. It can be irritating but not contagious.

Patients with atopic dermatitis are at risk of developing hay fever, food allergies, and asthma.

Reference:

The study titled "The association between atopic eczema and lymphopenia: results from a UK cohort study with replication in US survey data" was published in the Journal of the European Academy of Dermatology and Venereology.

doi:10.1111/jdv.18841