Global prevalence of atopic comorbidities in prurigo nodularis: A systematic review and meta-analysis

Summary: Abstract Body: Prurigo nodularis (PN) is a chronic pruritic disorder characterized by neuronal sensitization and dysregulated type 2 inflammation. Clinical evidence suggests that atopic/allergic disorders with shared inflammatory pathophysiology may commonly co-occur with PN, but the extent of their comorbid presence in PN patients remains unclear. Per PRISMA guidelines, we conducted a systematic review and meta-analysis to assess the global prevalence of atopic comorbidities in PN. Embase, PubMed, CINAHL, and Cochrane databases were searched for original studies with clinician-diagnosed PN reporting comorbidities. Reviews and qualitative research were excluded. Pooled prevalence proportions were estimated using a random-effects model for comorbidities reported in ≥3 studies. Of 3,361 abstracts screened, 39 full-text articles were reviewed, and 26 were included (n=33,206 PN patients). The pooled prevalence of AD was 39.1% [95% CI, 27.8%-50.5%] (n=7,788; 26 studies), with high heterogeneity (I2 = 99.9%, p < 0.001). Pooled prevalence of allergic rhinitis was 30.0% [13.7%-46.2%] (n= 1,775; 12 studies); asthma prevalence was 16.0% [10.2%-21.8%] (n=4,261; 14 studies); chronic urticaria was reported in 3 studies with a pooled prevalence of 4.9% [95% CI, 2.0%-15.4%] (n= 462). Similar high heterogeneity was observed across all analyses. Allergic conjunctivitis (n=72; 4 studies) yielded non-significant results with negative confidence intervals; food allergy was not measured frequently enough to be analyzed. Reference arms were lacking in most studies, preventing calculation of pooled odds ratios of association. These data show that atopic comorbidities, especially AD, allergic rhinitis, and asthma, are quite common among patients with PN. Given an evolving systemic treatment landscape for PN with multiple new and emerging treatments with distinct immunologic mechanisms of action, baseline comorbidity assessment may help guide optimal therapeutic selection. Natalia Chalupczak¹, Carmen Li¹, Christy Chang², Meredith Polaskey¹, Raj Chovatiya¹ 1. Rosalind Franklin University of Medicine and Science Chicago Medical School, North Chicago, IL, United States. 2. University of Illinois Chicago College of Medicine, Chicago, IL, United States. Clinical Research: Epidemiology and Observational Research