Assessing Disease Severity and Diagnosing Psoriasis

Brad Glick, DO, MPH: How is disease severity assessed and how have the definitions evolved, Neal?

Neal Bhatia, MD: I will take what we have learned out of clinical trials and see if we can translate it to English, because the biggest part of assessment starts when you walk in the door. The Investigators’ Global Assessment, or IGA, is an underutilized tool in the clinic. We have all done clinical research in the field of psoriasis, we know the second we walk in the door what the patients’ gradings are in terms of mild, moderate, and severe. I think that is something that should be part of clinic notes for everyone seeing patients with psoriasis. You should always include the severity in your physical examination and your assessment, just from the standpoint of that. The PASI [Psoriasis Area and Severity Index] score is underutilized in terms of the scaling, erythema, and plaque elevation. I think we need to do a better job, as a whole, in making sure all clinicians who do not do trials are still using those terms when defining body surface area [BSA], like 1% being the palm of the hand of the patient, and we can measure that very quickly in the clinic. Maybe we need to understand even more the definition of the integrity of the plaque so that we can follow their progress. I think, in terms of discussion of disease severity, it goes back to simple definitions, but in the end these measures also help us quantify the severity when we are trying to get the drugs covered, measure outcomes, and translate to quality of life extremes. I think we need to understand the way we define psoriasis, and not just how bad it is. We use some objective measures that we can translate. I think all of that would have some good utility for clinicians who are either just starting out or who are having trouble getting biologic agents covered.

Brad Glick, DO, MPH: Erin, do you have additional comments?

Erin Boh, MD, PhD, FAAD: Yes, Brad; I would like to parlay what Neal said. The most important thing is to document this. You walk in the room, and you see 25% body surface area. I think multiple ways of documenting is good—saying severe, yes, because then you are going to get 1 label to get your drugs approved, but also give the BSA. There is your global assessment. Any of those words you can do because insurance companies are looking for those buzzwords to say, “Is this patient severe enough to get it?” It won’t cut it if you have genital psoriasis and you say it is severe, or you say it impacts 4%.

Neal Bhatia, MD: You said it before, but we all up-code severity when scalp and nails are involved. We all up-code our erythema in skin of color, which I think is very important. We’ve even talked about geographic tongue having a bit of an up-code in psoriasis. All of these little parts of the physical exam could really add to the definition of severity when it comes to classifying these patients. I think even what you said before about genitals, we cannot be shy about asking patients to show us what is going on down there as well.

Erin Boh, MD, PhD, FAAD: Document—it is the big D; if you do not document it, you will not get anything covered.

Brad Glick, DO, MPH: I feel like my electronic medical records, dare I say this, have a very nice section where it allows me to put in these percentages, documentation, and IGA. It has been a nice addition for me, because when I was documenting on paper, I did not do this as often as I do now. I have been able to make it more crystal clear. Before we move on, George, do you have any comments in this area, too, about disease severity assessment?

George Han, MD, PhD: I want to echo some of these things. I think the 2 things that make us slightly uncomfortable when asking patients about their condition are the genitals and joints because of different reasons. I think the genital one may be obvious; we do not necessarily want to ask because it is private, but we should. We are taking care of them. The joints, also, are tough because we often figure people respond, and then you get into this rabbit hole of, “Do you have joint pain?” “Well, yes. My back hurts.” “How does the back hurt? Is there morning stiffness?” I think, sometimes you do not necessarily want to spend half an hour talking about joint pain, but that should not stop us from asking. There are great tools out there to help us with asking that. There are a number of validated tools that are pretty quick to implement that can help us. I think back also to discussing psoriasis with—I am actually in the midst of an argument right now with a paper that I am reviewing with some European authors because we had a little disagreement about what defines moderate to severe. 

They were making the point that, over there, they look at PASI 10 as the threshold for moderate to severe/eligible for systemic treatment. I wonder if that is because of socialized medicine or what the reasons are, but everybody has slightly different definitions. I find that nowadays I am reaching for systemic treatments for patients with less body surface area because either they have more important sites on the scalp that are affected, debilitating, and are very symptomatic, or because some people just make a lifestyle choice. Would I rather inject something relatively frequently or be smearing ointments all over myself, worrying about getting them on my clothes and sheets and things like that?

Erin Boh, MD, PhD, FAAD: It is not hard to do, and if you do not have the time to do it, get out your questionnaire. We have a questionnaire that I give to new patients. They sit in the room and wait for me. I do not mean to make them wait, but they do, and so while they are waiting they can fill out their questionnaire: where is there stiffness in the morning? Which joints hurt? For new patients, I take off their shoes because people have swollen toes and they will never say a word. If you do not ask, you do not know. Even if you do not have a lot of time—because you are right, George, you will end up with patients saying, “Oh my gosh; I hurt. Let me tell you what I did last time, blah, blah.” You will not get anywhere, but if you give them the paper, let them answer the questions, and then your scribe, your medical student, or somebody brings you that. 

Then you have it all answered before you walk in the room, and that is very useful because we want to keep our patients because I think we do treat them best. I want to throw in one thing about people slathering on topicals. Most dermatologists give out topicals all the time. If you look at the data, in 2018, the United States spent $53 billion or some crazy amount of money on topicals. It was more than any other treatment, including all biologics. We spend a lot of money on topicals, and people are not happy. If you have a woman with a bunch of hair, and you tell her to put topicals on every day and it takes her an hour or an hour and a half to do her hair, she is going to go someplace else. You need to realize that it is severe for that person. I think we are lucky that, in the United States, we can go down that road and people in maybe Britain and other places have more difficulties getting the biologics covered. For people who have had scalp psoriasis or difficult-to-treat psoriasis, it is not easy slathering on topicals, and it is not cheap. I think it behooves us to teach others that same thing. When people are happy, they are more productive at work, in their personal life. I think we need to listen to that in people. Sometimes it does take a minute, but I think it is worth doing because people, in the end, will be happy.

George Han, MD, PhD: How do you tell if somebody is biologic ready? I call it the “grocery bag” sign. They bring in the grocery bag with all the ointments and creams and stuff they have been given by other people.

Erin Boh, MD, PhD, FAAD: That is a pearl.

Brad Glick, DO, MPH: No question. What is the differential diagnosis for plaque psoriasis? When you look at the patients with these scaly eruptions, it is not always right out of a textbook, so what else are you thinking about?

George Han, MD, PhD: I think with classic psoriasis, we see a lot of it and it is our bread-and-butter, but it is good to go back to approaching differential diagnoses. I put this in the papulosquamous category; similar to psoriasis, we have seborrheic dermatitis. There is this crossover sebopsoriasis that, depending on whether you believe in or not, does exist out there. But we also think about parapsoriasis, right? Mycosis fungoides, in certain forms, we may be concerned about seeing in our patients. Then we have all the pityriasis form patterns. You have pityriasis rosea, and secondary syphilis looks similar to that—the great mimicker. Then there are certain fungal infections, tinea corporis and tinea versicolor, when very extensive, can somewhat mimic psoriasis as well. There is PRP, or pityriasis rubra pilaris. Subacute cutaneous lupus erythematosus, SCLE, is another kind of more annular papulosquamous entity that can mimic psoriasis in some cases. In certain patients, you might even think about lichen planus, with similarly bumpy, demarcated, scaly lesions. It is good to think about whenever you have that atypical case. Usually, we do not have to biopsy for psoriasis, but it is good to take a step back, get a little history, and consider doing a biopsy, or scraping, or whatever may be necessary.

Brad Glick, DO, MPH: Wonderful; well done. 

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Transcript edited for clarity.