Alopecia Areata is Associated with Atopic Diathesis; Results from a Population-Based Study of 51,561 Patients

Alopecia Areata is Associated with Atopic Diathesis; Results from a Population-Based Study of 51,561 Patients:

Publication date: Available online 6 February 2020

Source: The Journal of Allergy and Clinical Immunology: In Practice

Author(s): Khalaf Kridin, Yael Renert-Yuval, Emma Guttman-Yassky, Arnon D. Cohen

Abstract

Background

Evidence of Th1/interferon (IFN)γ over-activation as major pathogenic driver somewhat conflicts with data supporting robust allergic background in alopecia areata (AA) patients. Previous investigations of immunologic dysregulations show both Th1 and Th2-related markers are over-expressed in AA. Clinical correlations in large populations may shed light on the immune pathways most likely to result in the clinical phenotype of AA.

Objective

To investigate the atopic comorbidities among patients with AA in a large, population-based study.

Methods

This is a cross-sectional retrospective study of AA patients and a matched comparison group, analyzing the associations between AA and four atopic comorbidities: asthma, atopic dermatitis (AD), allergic rhinitis, and allergic conjunctivitis. Chi-square and t-tests were used for univariate analysis, and logistic regression model was used for multivariate analysis. The study was performed utilizing the computerized database of Clalit Health Services ensuring 4.4 million subjects.

Results

The study population includes 51,561 AA patients and 51,410 matched control subjects. The prevalence of asthma (7.8% vs. 6.5%; OR 1.22; 95%CI 1.17-1.28, p<0.001), AD (3.9% vs. 2.6%; OR 1.55; 95%CI 1.44-1.66, p<0.001), allergic rhinitis (16.0% vs. 12.8%; OR 1.29; 95%CI 1.25-1.34, p<0.001), and allergic conjunctivitis (23.5% vs. 19.6%; OR 1.27; 95%CI 1.23-1.30, p <0.001) was significantly higher among patients with AA as compared to matched control subjects. AA patients also had significantly higher probability to have more than one atopic comorbidity, with increasing OR as the number of concomitant atopic conditions increases.

Conclusion

Our analysis supports the previous literature and provides strong generalizability of significant atopy in AA patients, suggesting Th2 pathogenicity in AA, and challenging the traditional view of AA as a single axis, Th1-centered disease.