The National Psoriasis Foundation (NPF) has issued a new position statement on psoriasis disease severity that clarifies the definition of severity in an effort to increase access to systemic therapy for appropriate patients.
According to the new criteria, psoriasis severity will be defined as either “mild” or “moderate to severe.” The NPF explained that the update has been made to address lingering misconceptions that can limit patient access to appropriate care.
According to Andrew Blauvelt, MD, chair of the NPF Medical Board, outdated labels create ambiguity about psoriasis, which is far more than a benign cosmetic condition.
“This is a chronic, systemic inflammatory disease that can lead to serious health consequences, including psoriatic arthritis and cardiovascular disease,” said Dr. Blauvelt. “Under-treatment of psoriasis places patients at high risk for developing these very serious issues. It was important for us to draw a very clear line for health care providers and insurance. We are saying that there is no middle ground and no ambiguity. A patient should be considered as having either ‘mild’ psoriasis, which can be managed with topical therapies, or ‘moderate-to-severe’ psoriasis, which makes these patients candidates for advanced therapies.”
Two-Tiered Treatment
Historically, in both clinical practice and clinical trials, psoriasis severity was classified as mild, moderate, or severe depending on the percentage of body surface area covered by psoriatic lesions. Using this three-class system, however, could result in diagnoses that underestimated the severity of disease when high-impact sites such as the groin, hands or feet are involved, or when topical therapy yields an inadequate response, according to Dr. Blauvelt.
“Psoriasis severity is not all about body surface area involvement,” Dr. Blauvelt explained. “It also is dependent on where the psoriasis is and whether it has failed topical therapy.”
The terms “mild” and “moderate to severe” were retained because they are widely used by patients, clinicians, and in the literature, Blauvelt said, but the new psoriasis severity classification best reflects current clinical practice.
“There really is no third category,” he added. “Practically speaking, there has always just been two categories: Am I going to treat inside or outside?”
Increasing Access
The NPF’s new guidelines emphasize the extent of disease as well as the location of lesions and past treatment history, and they align with current best practices. The International Psoriasis Council (IPC) had already published a new definition of psoriasis severity limiting the classifications to two categories in 2020. The IPC criteria recognized two categories of psoriasis patients: candidates for topical therapy or candidates for systemic therapy, and many international groups endorsed and adopted the IPC criteria.
The NPF position statement highlights a minor change from the IPC, using the term “high-impact sites” as the preferred nomenclature rather than “special areas” when referring to psoriasis affecting the scalp, face, palms or soles, intertriginous areas, genitalia or nails.
Dr. Blauvelt described the new criteria as “patient-centered” and noted their practicality for dermatologists.
“Patients who have historically been denied coverage because they have not had 10% body surface area involved can now obtain systemic therapy if they have disease in a high-impact site or if they have failed topical therapy,” he said. “This should increase access for appropriate patients to systemic therapy.”
