In this podcast, Neal Birnbaum, MD, discusses the challenges of treating progressive psoriatic arthritis, why certain patients progress to more severe disease, and how to change medication when needed.
Neal Birnbaum, MD, is director of the Division of Rheumatology at California Pacific Medical Center in San Francisco, and a clinical professor of medicine at the University of California San Francisco.
Podcast Transcript:
Announcer: The content for this topic is independent and is made available with support from Amgen.
Rebecca Mashaw: Welcome to the special installment of “Podcasts360,” your go‑to resource for medical news and clinical updates. I’m your moderator, Rebecca Mashaw, with Rheumatology Consultant. This is the first part of our new series on diagnosing and treating psoriatic arthritis, which affects approximately 1 million people in the United States.
With us today is Dr Neal Birnbaum, chief of the Division of Rheumatology at California Pacific Medical Center in San Francisco, and clinical professor of medicine at the University of California at San Francisco. He’s going to be talking to us today about the worsening of disease in psoriatic arthritis.
Thanks for joining us today, Dr Birnbaum. What causes psoriatic arthritis to progress to more severe disease in certain patients? Are there environmental lifestyle factors that can worsen disease?
Neal Birnbaum: There is not a lot known about this particular question. Let me take the second part of it first. There’s very little in the way of environment involved in any of the forms of inflammatory arthritis. The only known environmental factor in rheumatoid arthritis happens to be smoking. Not sure if that’s also a factor in psoriatic arthritis.
All patients ask about diet, activity, supplements, whatever, and there is no scientific evidence that says any of those play a significant factor. The other questions always get down to, why does a particular person have psoriasis? Why did they get arthritis? Is there anything they could have done about this?
In general, the answer is bad luck. We know that psoriasis occurs in a fairly significant number of the population, probably [1% or 2%]. Of those patients maybe 20, 25% will develop a form of arthritis related to their psoriasis.
RM: Is there any relationship between the relative severities of psoriasis before a patient develops psoriatic arthritis and the severity of the psoriatic arthritis itself if it does develop?
NB: It’s also unpredictable. There would be the assumption perhaps that patients with the most severe skin involvement with psoriasis would have the most severe arthritis. That’s true to a slight degree. However, there are plenty of patients who have very significant arthritis and minimal psoriasis, and vice versa.
RM: When a patient progresses from psoriasis to psoriatic arthritis, or when psoriatic arthritis gets worse, what first steps would you advise rheumatologists to take in helping to mitigate the effects of the disease on the patient?
NB: It’s more a question of assessing the patient and deciding whether the current therapy is adequate, or whether they need to make a change to a more aggressive therapy program.
RM: When a change in medication for a patient with psoriatic arthritis is indicated, how do you proceed?
NB: First, we wanted to assess the severity of psoriatic arthritis. There’s ways to look at this. There are a number of very formalized ways which are generally used only in clinical trials and not nearly as much in day‑to‑day practice.
Certainly, looking at the severity of the skin involvement, and that can be done in conjunction with our dermatology colleagues. Then looking at the joints, the number of joints, the amount of inflammation that we see, are there changes on x‑ray, are there laboratory abnormalities. Now there are no serologic changes in psoriatic arthritis; there’s no blood test that says, “Oh, you have this,” but the sedimentation rate and the CRP, C‑reactive protein, are sometimes evidence of very active disease.
We’re also looking at patient function. How are they doing with the activities? How much is this arthritis interfering with the things they both need and want to do, both from occupational activities, home activities, recreational activities?
RM: Is psoriatic arthritis diagnosed primarily or exclusively based on clinical symptoms?
NB: The diagnosis of psoriatic arthritis is a clinical diagnosis. There are some characteristic joint patterns—there are 4 or 5 different patterns that are recognized that we look for—and we see if those occur in the setting of psoriasis, either current or prior psoriasis. Sometimes, where there is a family history of psoriasis, even though the individual doesn’t have psoriasis. There are some patients where we are looking at a pattern of arthritis that seems to fit, even though there’s no history of psoriasis. That’s sometimes called psoriatic arthritis sine, without S‑I‑N‑E.
In that situation, the patient may develop their psoriasis after they’ve had the arthritis. That’s not the usual situation, but it certainly occurs. Usually, the psoriasis has been present for some period of time before the development of joint development, and not infrequently, they develop rather simultaneously.
RM: Is patient’s age a factor at all in the progression of psoriatic arthritis?
NB: No. I think that psoriasis occurs across a spectrum of ages, from very young to very old. One of the things we have to watch out for is that not every joint pain in a patient with psoriasis is psoriatic arthritis. That patients may have osteoarthritis. That’s going to be more common as the population ages.
Differentiating whether arthritis in any particular patient is psoriatic arthritis vs degenerative arthritis can be difficult. Again, it’s clinical. You look somewhat at the distribution of the joints, the pattern of involvements, the look, the feel of the changes, for instance, in the small joints at the end of the fingers, which is a common sight for both osteoarthritis and psoriatic arthritis.
Osteoarthritis is a bony enlargement. It’s hard, and it’s usually not inflamed looking worse. Psoriatic arthritis, maybe have a squishy feeling because there’s inflammation of the joint lining the ends of the fingers may have psoriatic lesions. It’s quite common to have psoriasis of the nails on the fingers that have the worst arthritis.
RM: Do you have any final thoughts for rheumatologists about the challenges of working with patients who have progressive psoriatic arthritis?
NB: We’re always looking at the overall picture of the patient. What’s the control of their skin disease, because the advantage of the newer agents is you have good control of both skin and joints at most occasion.
Periodic reevaluation of seeing the patient, talking to the patient, getting an idea of how much they’re being bothered, what’s their pain level, what’s the duration of morning stifness, what problems do they have with activities of daily living.
Some rheumatologists are going to do formal joint counts or use any of the various assessment tools that are out there to look at disease activity.
Serial x‑rays, not taken every month but maybe every year or two, may also provide evidence of disease progression. The assessment is difficult; it takes some time and sitting with them, and really assessing them carefully as to the effect of the disease on their daily lives.
Oftentimes, I won’t make a change the first visit that someone has some increase in symptoms unless it’s severe because there are certain ups and downs that occur in the course of therapy. Overall, the management of inflammatory arthritis, including psoriatic arthritis, has improved so dramatically over the last 20 years.
We have many, many options. Today, in psoriatic arthritis, there’s almost a problem remembering all the different names for the drugs because it’s been a dramatic change in the last two decades.
RM: Thank you so much for your time today, Dr Birnbaum. We really appreciate your insights into the subject of progression in psoriatic arthritis.
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