Identifying Clinical Manifestations of Plaque Psoriasis

Christopher G. Bunick, MD, PhD: We’re going to go on to our next question and discuss a little about the clinical manifestations of plaque psoriasis. Dr Wu, could you talk about not only the clinical manifestations but a little about the progressive nature of psoriasis as a whole? Is there an importance to early diagnosis and treatment vs a later diagnosis and treatment? How do you see the progressive nature and when you start treatment affecting the actual clinical appearance of your patients?

Jashin Wu, MD: Sure. The clinical manifestation of psoriasis tends to be thick erythematous plaques, characteristically with a silvery scale on the elbows and knees. It can also be on the scalp. Those are probably the most common locations, but it can certainly be outside of these areas as well. Many times, these patients will scratch and may have some bleeding there. That would be considered the Auspitz sign when they have bleeding right where they’re picking off the silvery scale. They can certainly have psoriasis in other areas as well. For nail psoriasis, they can have nail pitting, salmon patches, and onychomycosis-like changes. Those are very common scenarios of the nails.

They can also have inverse psoriasis, which is where the psoriasis is maybe a little less silvery and has more of a macerated appearance. These would be more in the armpit or groin areas. They can have pustular type psoriasis, which could be generalized pustular psoriasis. That can be more of a medical emergency where they have almost whole body psoriasis with pustules throughout the whole body. They can be febrile or very toxic appearing. They’ll probably go to the ED [emergency department]. They might have to be hospitalized. Then there’s also the more localized palmar pustular psoriasis, usually on the palms and soles. That’s a slightly more difficult variant to treat. They can also have erythrodermic psoriasis, with the whole body filled with psoriasis. This could also be more of a medical emergency.

There’s also guttate psoriasis. Guttate means drop-like. These patients tend to be on the younger side. They can have these drop-like lesions more on the trunk area. They’re usually younger patients, like children or adolescents. Usually they’d have a strep throat infection first, in which case they could have the guttate flare. Then they could have that treated or it might resolve on its own, but if they have another guttate, they have another strep throat infection, and they can have another flare of guttate psoriasis. Here’s one way you potentially could prevent having future psoriasis. There are some studies that show that a tonsillectomy could potentially prevent the guttate psoriasis from becoming a plaque-type psoriasis.

In terms of the progressive nature of the disease, patients usually present with psoriasis, the skin disease, first. About 10 years later on average, they can have the joint manifestations of psoriasis, psoriatic arthritis. With the skin manifestation, you can treat the disease. That may have some clearance or post-inflammatory changes, but there’s no scarring per se. With psoriatic arthritis, that’s different. If you don’t treat the psoriatic arthritis, it can be slowly progressive and then form many deformities in their joints and they can have loss of range of motion and lots of severe issues with that. In general, it’s better to treat patients sooner rather than later. I advocate using a systemic agent if they have more severe disease.

Christopher G. Bunick, MD, PhD: Thank you for that. Let me ask you a question about the patients with psoriatic arthritis. In your own practice, how often do you treat these patients with both plaque psoriasis or psoriatic arthritis with biologics by yourself vs bring in a rheumatologist to help co-treat the patient?

Jashin Wu, MD: That’s a great question. Generally speaking, if they have both severe psoriasis and psoriatic arthritis, I’ll treat it myself. I’d typically put them on an interleukin-17 inhibitor or TNF [tumor necrosis factor] inhibitor, as Dr Lebwohl mentioned. However, if they have more mild disease of the skin but they have psoriatic arthritis and might not necessarily qualify for one of these biologic agents based on the psoriasis itself, I may get rheumatology involved to see if they could be put on something other than a biologic first. But sometimes in those cases, the wait time for rheumatology is much longer than it is for dermatology, so I still may treat them with one of those agents myself.

Christopher G. Bunick, MD, PhD: Excellent. Let me ask you about body surface area. There’s a lot of emphasis on body surface area, particularly documenting the psoriasis affected surface area in medical charting or notes in order to satisfy insurance companies that want a certain body surface area before they’ll approve a biologic. This might not be the right thing, because you have some people who have scalp psoriasis and it’s only localized on the scalp, and it can be very severe. I wanted your opinion on this. What do you think about body surface area? What about patients who have severe scalp psoriasis and the effect on quality of life that psoriasis can have even when it’s a very small body surface area affected?

Jashin Wu, MD: Right. Traditionally, body surface area can be defined as less than 3% being mild disease, between 3% to 10% being moderate disease, and greater than 10% being severe disease. For some patients, this is a reasonable way to characterize the severity of the disease, but certainly not for all patients. As you mentioned, if they have severe scalp disease, that would be about 2% or 3% of the body. I’ve had some patients who failed clobetasol solution, something like methotrexate, and all the other oral agents. Then I’d actually put them on a biologic.

The International Psoriasis Council put out a paper in the last year or so where they recommended maybe changing the severity classification. Say they failed any topical agent. Then they should be considered for any systemic agent at that point. They don’t necessarily need to have a certain amount of body surface area per se. And if they have a poor quality of life or a very specific area, like right on the face—maybe they have that 1% but it’s right in the middle of their face—that to me would be a reason for them to get a systemic agent rather than purely topical agents.

Mark G. Lebwohl, MD: The [National] Psoriasis Foundation years ago said the same thing. In their guidelines of care, they consider involvement of certain body areas like palms and soles, scalp, or genitals as being severe enough that just having those would justify systemic therapy and specifically biologic therapy. As usual, I’d agree with 99% of what Jashin said. The 1% difference, which may be a function of the states we’re in, is that in New York, I no longer have to fail methotrexate or oral systemics to get to a biologic.

Christopher G. Bunick, MD, PhD: Yes. That’s very important, having patients be able to get direct access to some of these newer technologies that are certainly revolutionizing the treatment of psoriasis. In my experience with scalp psoriasis in general, some patients who have 1% or 2% body surface area affected may be miserable and their quality of life greatly affected. And then I have some patients who have body surface area at 90% and they’re happy as a clam. Quality of life isn’t always body surface area.

Transcript edited for clarity.

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