Prurigo Nodularis Diagnosis Centers on Clinical Recognition, Not Biopsy, Dr. Elmariah Says

A pragmatic, clinically driven approach is necessary for diagnosing prurigo nodularis (PN), and a biopsy is often unnecessary when key features are present, according to a talk by Sarina Elmariah, MD, FAAD, at the 2026 American Academy of Dermatology (AAD) Annual Meeting.

“It is these three diagnostic features—itch, nodules, and some degree of chronicity—that really define the disease,” Dr. Elmariah said, noting that chronicity typically reflects symptoms persisting beyond 6 weeks alongside evidence of scratching or manipulation.

According to Dr. Elmariah, PN remains a diagnosis best made at the bedside.

“A thorough clinical assessment is where you really drill down on making this diagnosis,” she said.

While biopsies are sometimes performed, particularly prior to referral, she cautioned against overreliance on histopathology.

“You don’t need to do a biopsy. … It is not necessary to confirm your instinct,” she said, adding that biopsy results are often nonspecific and may not meaningfully alter management.

Dr. Elmariah emphasized three core criteria—itch, nodules, and chronicity (>6 weeks)—alongside structured evaluation of symptoms, lesion morphology, and comorbidities.

A detailed patient history remains essential, particularly in understanding how patients describe pruritus.

“Sometimes, they won’t call it itch,” Dr. Elmariah noted. “You have to make it central to the patient, in their language and how they experience their disease.”

Beyond symptom description, clinicians should carefully assess lesion type and distribution. While classic nodular lesions account for the majority of cases (approximately 60% to 70%), Dr. Elmariah noted increasing recognition of clinical heterogeneity.

Patients may present with smaller papules, larger plaques, or mixed morphologies.

“You will often see a plaque with a more discrete, keratotic center,” she said, emphasizing that multiple lesion types frequently coexist in a single patient.

In severe cases, diagnostic complexity may increase. Dr. Elmariah described patients with extensive ulceration who had previously been mischaracterized as having alternative conditions, including psychocutaneous disorders.

“There can be multiple pathologies,” she said, reinforcing the need for careful clinical correlation.

Dr. Elmariah also stressed the importance of evaluating disease severity and associated conditions. Symptom burden, including itch intensity and sleep disruption, should guide treatment decisions and provide a baseline for monitoring response.

“We need to quantify itch and understand its impact,” she said, noting that PN frequently disrupts sleep and daily functioning.

Additionally, identifying dermatologic and systemic comorbidities can inform therapeutic selection. While not always determinative, these factors may influence the choice of systemic or targeted therapies.

Ultimately, Dr. Elmariah said that PN is not only a cutaneous disorder but a disease with profound quality-of-life implications. Patients may experience significant physical discomfort, sleep disturbance, and psychosocial burden.

“This is a disease with a high burden,” she said, reinforcing the need for timely recognition and intervention.