Prurigo nodularis prevalence proves higher than previously estimated

Key takeaways:

• Prurigo nodularis prevalence was 0.19% which is higher than previous estimates of 0.02% to 0.07%.
• Older individuals are disproportionally affected by prurigo nodularis.

Prevalence of prurigo nodularis is higher than previously estimated and is associated with many comorbidities, according to a study.

“[Prurigo nodularis (PN)] is a chronic inflammatory skin condition characterized by intensely pruritic nodules on the extensor surfaces of extremities and on the trunk,” Marina Z. Joel, BS, of the department of dermatology at The Johns Hopkins School of Medicine, and colleagues wrote. “The prevalence of PN remains poorly characterized.”

In this study, the authors investigated the epidemiology of PN using data from All of US, a National Institutes of Health database that contains health information about U.S. adults.

The study compared 701 participants with PN with 368,281 participants without PN.

Results showed that the overall prevalence of PN was 0.19% (95% CI, 0.18%-0.2%) which stands in stark contrast to previous estimates of 0.02% to 0.07%.

PN prevalence was found to increase with age by 0.02% (95% CI, 0.002%-0.03%) for those aged younger than 30 years and 0.35% (95% CI, 0.31%-0.39%) for those aged older than 70 years. In fact, patients with PN were found to be significantly older than those without PN (mean age, 64.8 years vs. 54.8 years).

Patients with vs. without PN also experienced higher rates of comorbidities, with depression being the most prevalent (54.4% vs. 18%) followed by type 2 diabetes (43.2% vs. 12.1%; P < .001 for both).

The rates of other common comorbidities among patients with PN included 29.4% with chronic kidney disease, 23.3% with COPD, 20.3% with congestive heart failure, 15.5% with atopic dermatitis, 7.4% with HIV and 6.4% with chronic hepatitis C. In contrast, the rates of these comorbidities among the healthy controls were all less than 6% (P < .001 for all).

The study also found an elevated prevalence of PN among participants with the aforementioned comorbidities, especially among those with atopic dermatitis (2%; 95% CI, 1.62%-2.37%), congestive heart failure (1.13%; 95% CI, 0.95%-1.32%) and HIV (1.12%; 95% CI, 0.82%-1.43%).

The authors state that this may “suggest that underlying comorbidities play a role in [PN’s] development, likely through immune dysregulation.”

PN prevalence was also highest in Black (0.22%; 95% CI, 0.19-0.26%) and white participants (0.21%; 95% CI, 0.19%-0.23%) followed by Asian (0.09%; 95% CI, 0.04%-0.14%) and Hispanic participants (0.09%; 95% CI, 0.07%-0.11%).

While this study offers new insights into the epidemiology of PN, according to the authors, “further research is needed to characterize the disease burden of PN and explore potential contributing factors to its development.”