Measuring Severity Beyond PASI

While Psoriasis Area and Severity Index (PASI) offers great utility in clinical trials, grading severity is not as cut-and-dried in an appointment room. Elizabeth B. Wallace, MD, FAAD, shares what dermatologists should know about measuring psoriasis severity in daily practice, including tools she uses and why quality of life should be considered.

Dr Wallace is an assistant professor of dermatology in the department of dermatology at University of Colorado School of Medicine and Anschutz Medical Campus in Aurora. She is also the co-director of the Connective Tissue Disease Program, co-founder of the Rheumatology-Dermatology clinic, and assistant director of Clinical Trials.

Transcript
Dr Wallace: The PASI, the Psoriasis Area and Severity Index, is one measure to determine psoriasis severity and other tools that are users things like body surface area, which is something we might use in the clinic or the IGA, the Investigator Global Assessment.

The PASI is really having a role in clinical trials to determine the severity of psoriasis at the initiation of a trial and then also be able to track patient improvement and disease severity over time. There are different elements to the PASI including the erythema, different lesions, the induration of individual plaques, the amount of scaling, and these are all different characteristics that go into the calculation of the PASI Score. 

Determining disease severity using the PASI can have value because it is a validated tool, and we can track improvement over time in those areas like clinical trials. I think there are certainly a range of severities: mild, moderate, and severe disease. I do think that it needs to be put together with everything else, quality of life. The PASI, even if someone has a mild disease severity, does that also reflect the impact of the psoriasis on their quality of life? I think there are different things that we need to take into account when evaluating the patient, determine how we want to treat the patient, and also measuring improvement with the PASI just being one tool that we can use.

Things that I use in my practice routinely with patients are body surface area. I also very much use the Investigator Global Assessment. That's to track improvement over time so we can show patients how they're doing. It also, on the logistical side of things, helps us with insurance approval for certain medications and then quality of life. 

Just having a very open and honest conversation and open dialogue with patients about how they're doing and how they're feeling, but then also knowing that there are these validated measures out there to track quality of life over the time, such as DLQI.