It’s one thing to study outcomes from plaque psoriasis treatments in clinical trials, it can be quite another to treat psoriasis patients in clinical practice, say researchers writing in Seminars in Cutaneous Medicine and Surgery.
The article, which appears in the February issue, explains that while body surface area (BSA) scores are used by physicians to measure outcomes, it doesn't take into account the outcomes patients seek — which may be entirely different. For many, quality of life holds more value than achieving specific treatment outcomes.
“PASI is a research tool, so patients are not likely to understand it. It's not intuitive. BSA is better, but if you tell somebody their 2% BSA (which is all on the face) is mild, they may not be happy with you,” said Jashin J. Wu, M.D., director of dermatology research at Kaiser Permanente Los Angeles Medical Center and the study's corresponding author.
The article focuses on goals for plaque psoriasis therapies. The authors recommend using a treat-to-target strategy with patient-centered assessments to relieve symptoms and stop disease progression.
Among the validated patient-reported assessments: The Dermatology Life Quality Index and Psoriasis Symptom Inventory. These allow dermatologists and others to collaborate with patients to set realistic, achievable goals that satisfy individual patients.
Determining an acceptable level of psoriasis improvement for a population of patients isn’t easy. In one study of more than 90,000 psoriasis patients, researchers suggested an initial goal of less than 10 percent body surface area for patients on psoriasis therapy. But that goal, or even the National Psoriasis Foundation’s treat-to-target BSA goal of 1% or less, may not yield positive quality of life scores, they write.
“Location matters, and BSA doesn't necessarily address the hardest locations, including the face, palms, soles, genitals,” Dr. Wu said.
National Psoriasis Foundation consensus targets for psoriasis treatment can help dermatologists and their patients set realistic goals. One example, the Foundation’s treat-to-target consensus suggests allowing three months for patients to respond to therapy. Other acceptable targets include achieving 3% or less body surface area after three months of moderate-to-severe psoriasis treatment or 75% or more improvement in body surface area from baseline.
According to a commentary by Dr. Wu and colleagues published in June 2017 in Cutis, the authors propose a new nomenclature: a 75% improvement in BSA would be recognized as BSA75, a 90% improvement in BSA as BSA90 and a 100% improvement in BSA as BSA100. The classifications would be analogous to corresponding improvements in PASI 75, PASI 90, PASI 100 scores. While implementation of the categorization system wouldn’t assess important psoriasis aspects, such as quality of life, symptoms, location of involvement and more, it might encourage physician-patient conversations and help direct modifications to disease management and treatment therapy, they write.