International Psoriasis Council

Advancing Knowledge. Enhancing Care.

Advancing Knowledge. Enhancing 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 a 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. IPC is also working to strengthen psoriasis treatment guidelines and guide future clinical trials of drugs targeting various severities of psoriasis.

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 would allow for more specific clinical severity criteria that can guide clinical decision-making to be more practical, meaningful, and better aligned with the severity of a patient’s disease.

image of computer with words expert commentary

Commentary: Psoriasis treat to target: defining outcomes in psoriasis

In moderate to severe psoriasis, there has been a long-lasting tradition to define outcome as a relative change from baseline PASI, with the classical PASI 75 being more recently replaced by PASI 90 or 100. However, this concept is dated, mainly due to the impressive development of anti-interleukin therapies and an increasing interest in real-world evidence.

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Bruce Strober





Central Connecticut Dermatology





United States





Herlev and Gentofte Hospital, University of Copenhagen








Oregon Medical Research Center





United States

Additional Resources

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


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.


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.