International Psoriasis Council

Advancing Knowledge. Improving Care.

Advancing Knowledge. Improving Care.

Recategorization of Psoriasis Severity


Disease severity criteria can significantly impact a psoriasis patient’s eligibility for treatment. While their disease may profoundly affect their quality of life, the current clinical definition of psoriasis severity is narrow. It does not account for the many potential challenges the disease may cause in a patient’s life.

In 2019, IPC began its disease severity reclassification project to redefine the criteria used for assessing disease severity that would better guide clinical decision-making to be more meaningful, practical, and better aligned with the actual severity of a patient’s disease.

This project seeks to challenge using the standard definitions of “mild, moderate, and severe” to determine treatment pathways. Through a robust Delphi process, IPC’s network of experts developed a consensus statement that redefines the criteria for patients who are candidates for systemic therapy. The statement is as follows:

Patients that meet one or more of the following criteria are candidates for systemic therapy:

  • Psoriasis lesions on 10% or more of body surface; OR
  • Psoriasis lesions on sensitive areas of the body (i.e., hands/feet, face, genitals, scalp); OR
  • Topical therapy failed to control symptoms.

Fast Facts

  • Typically, patients must have a PASI of 10 or 12 to be eligible for systemic treatments.
  • Despite this, patients with a PASI or BSA score below ten can experience significant impairment in their quality of life.
  • Reclassification allows for more specific clinical severity criteria that guide clinical decision-making to be more practical, meaningful, and better aligned with the severity of a patient’s disease.

IPC Resources


The Experts

Bruce Strober Headshot





Central Connecticut Dermatology


United States





Herlev and Gentofte Hospital, University of Copenhagen





Blauvelt Consulting, LLC
Lake Oswego


United States

Additional Resources

Below are resources from other organizations that support IPC’s recategorization of psoriasis severity.


Australian Consensus: Treatment Goals for Moderate to Severe Psoriasis in the Era of Targeted Therapies – Adult Patients. Foley, P, Gebauer, K, Sullivan, J, et al. Australas J Dermatol. 2023; 00: 1–12.

A study was conducted to update treatment goals for moderate to severe psoriasis. A modified Delphi approach was used, involving a comprehensive literature review and guideline evaluation. Consensus was reached on expanding the classification of psoriasis severity, incorporating quality of life measures, and widening the scope of high-impact sites. The study aimed to address challenges to timely and equitable access to targeted therapy, aligning with international recommendations and aiming to improve treatment outcomes and patient satisfaction.

Evolution of Patient Perceptions of Psoriatic Disease: Results from the Understanding Psoriatic Disease Leveraging Insights for Treatment (UPLIFT) Survey.
Lebwohl M, Langley RG, Paul C, Puíg L, Reich K, van de Kerkhof P, Wu HL, Richter S, Jardon S, Gisondi P.Dermatol Ther (Heidelb). 2022 Jan;12(1):61-78. doi: 10.1007/s13555-021-00635-4. Epub 2021 Oct 25.PMID: 34704231

The proportion of patients with at least a moderate effect of psoriasis on quality of life was greater among patients with involvement in at least one special area versus no special area involvement. In this international population study, the impact of the various special areas on quality of life is reported.

Impact of Psoriatic Disease on Quality of Life: Interim Results of a Global Survey
April Armstrong 1, Barbra Bohannan 2, Sicily Mburu 3, Ivette Alarcon 4, Torben Kasparek 4, Jihen Toumi 5, Susan Frade 4, Silvia Fernandez Barrio 6, Matthias Augustin 7 Dermatol Ther (Heidelb). 2022 Apr;12(4):1055-1064. doi: 10.1007/s13555-022-00695-0.Epub 2022 Mar 14.

The IPC disease severity recategorization is not a data-driven but a practice-driven categorization. To a large extent, psoriasis is a systemic disease that requires dermatologists to look more than skin deep. As systemic treatment for psoriasis may be indicated in patients with mild skin involvement suffering from systemic comorbidity, the holistic approach in the IPC definition is crucial.

Reassessing Psoriasis Severity

The National Psoriasis Foundation (NPF) addresses limitations in traditional psoriasis severity classifications, emphasizing the significance of “high impact sites” on patients’ lives. The NPF, along with the IPC, advocates for revised treatment criteria. Learn more about redefining psoriasis severity and treatment standards in the full article.


Dialogues in Dermatology: Categorizing Psoriasis Severity (Sponsored by Bristol Myers Squibb)
Listen as IPC Board Member and Vice President/President-Elect Bruce Strober discusses the categorization of psoriasis severity and its part in determining the correct therapy, in this Dialogues in Dermatology podcast.
In Conversation: A New Method of Classifying Psoriasis Severity from the International Psoriasis Council
In this three-part video series by Novartis, Dr. Bruce Strober and Dr. Andrew Blauvelt discuss the new IPC classification.
It’s Time for a Change: IPC Psoriasis Severity Reclassification (CME)
Listen as IPC Board Member Dr. Bruce Strober and IPC Councilor Dr. Andrew Blauvelt discuss the International Psoriasis Council’s rationale for changing psoriasis severity classification for treatment decisions and clinical trials in this NPF podcast.

Psoriasis is More Than Body Surface Area
IPC Board Member Dr. Andrew Blauvelt discusses when psoriasis should be considered severe and what that means for treatment choices, especially in high-impact areas like the scalp, nails, palms, soles, face, and genitalia.