Prurigo Nodularis: Features and Burden of Disease

During the 2023 Interdisciplinary Autoimmune Summit, Shawn Kwatra, MD, presented his session, “PN in Patients with Skin of Color.” He described the clinical features, pathophysiology, and burden of disease in prurigo nodularis (PN).

Dr Kwatra started with a diagram of how PN presents, which showcased papules or nodules with variability in size, ranging from a few millimeters to up to 2 to 3 cm. Additionally, excoriations and crusting are signs of disease activity. If chronic itch or pruritus is present, manifestations include hemorrhagic crusts on top of the nodules, which often have a bilateral distribution commonly seen on the arms and legs. He noted that the most common areas for PN include:

• Lower legs
• Upper arms
• Lower back

Next, he reviewed the significant heterogeneity in patients with PN. He noted that some patients have more erythema on their body, whereas others have more tissue fibrosis. He stressed that African American patients with PN have significant skin thickening and fibrosis, which can look similar to a keloidal plaque.

When discussing awareness of the disease, Dr Kwatra stated, “I suspect there is actually very poor disease awareness of PN, and the true number [of cases] is probably way higher. I would say there are over half a million cases in the United States, but with better disease awareness coming from the pharmaceutical revolution in terms of new therapeutics and trials, there is more attention being given to this disease.”

He continued by sharing how PN disproportionately affects middle-aged to older-aged patients, in addition to African American and Asian patients who may be more likely to have the disease. Regarding the quality-of-life impact and comorbidity burden associated with PN, he shared that the overall impact on quality of life can be severe. Typically, patients have had uncontrolled disease, with increased ambulatory, emergency, and inpatient visits alongside increased mortality.

He then continued with several comorbidities associated with PN, starting with mental health disorders or mood disorders such as anxiety and depression. “What I would say is that it is not that mental health disorders are causing PN. I would challenge that if any of us had intense itch or fibrosis and these skin nodules that are so psychosocially damaging, we would probably also develop many of these mood disorders,” Dr Kwatra added.  

Next, he reviewed the infectious disease comorbidities, noting that HIV is more likely in patients with PN. Additionally, he highlighted the many associations with chronic medical conditions, such as:

• Type 2 diabetes
• Chronic kidney disease
• Heart failure
• Thyroid disease
• End-stage renal disease

Finally, Dr Kwatra noted that it is unsurprising patients with PN who are hospitalized are more likely to experience these infections compared with the general inpatient population.

Reference
Kwatra S. PN in patients with skin of color. Presented at: Interdisciplinary Autoimmune Summit; April 26–28, 2023; Virtual.