Prurigo Nodularis Photos by--Johns Hopkins Medicine
A large cross-sectional study has found that prurigo nodularis (PN)—an uncommon but potentially debilitating skin condition—is more common among African-Americans and is associated with a number of systemic conditions, including HIV, chronic kidney disease, and diabetes.
“These are patients whose lives have been devastated by an unbearable, persistent itch that dramatically reduces quality of life on par with the most severe diseases treated by our specialty,” said lead author Dr. Shawn Kwatra in a June 14, 2018 press release. Dr. Kwatra is an assistant professor of dermatology at the Johns Hopkins University School of Medicine in Baltimore.
In addition to the immense discomfort from itching and scratching, said Dr. Kwatra , PN interferes with sleep and affects social interactions with people who may have a needless fear of contracting the non-infectious skin condition. However, he said that there has been a shortage of research into PN despite these quality-of-life impacts. In the release, the authors note the paper represents some of the first published reliable information from a racially diverse population about who likely develops this chronic condition, which is characterized by intensely itchy nodules that develop on the arms and legs that can generalize throughout the body.
The study, published online ahead of print in Journal of the American Academy of Dermatology (May 4, 2018), looked at records from 909 patients with PN collected over a five-year period. Investigators found that African-American patients were 3.4 times more likely to have PN than white Caucasians (Odds ratio (OR) 3.4, 95% confidence interval (CI) 2.9–3.9, p<0.001).
PN was also significantly associated with a variety of systemic, cardiovascular, and psychiatric co-morbidities when compared to race-matched controls. This included chronic kidney disease, chronic hepatitis C, chronic obstructive pulmonary disease, congestive heart failure, depression, and atopic dermatitis.
African-American patients with PN were 10.5 times more likely (OR 10.5, CI 7.9–13.9, p<0.001) to have HIV than race-matched controls with atopic dermatitis, and eight times more likely (OR 8.0, 95% CI 5.7–11.1, p<0.001) to have HIV than African-American patients with psoriasis. Dr. Kwatra and his team suggests these findings may be used not only in the clinical care of PN patients, but to form the basis for ongoing translational studies to develop novel treatments for the disorder, as there is currently neither a U.S. FDA-approved therapy nor a consistently effective off-label treatment for the condition.
In the release, Dr. Kwatra cautioned that the observed associations with other conditions do not demonstrate that PN causes these disorders, or vice versa.
However, he added, knowing the connections between PN and various health conditions could lead physicians to give patients more thorough evaluations to check for other conditions once they’re diagnosed with PN.