Clinical Manifestations of Psoriatic Arthritis

Anthony M. Turkiewicz, MD: Right. Sheetal, we’re going to move forward and talk about the basics of psoriatic arthritis, the clinical manifestation, thinking about how they present in your clinic. If you can, touch on perhaps some of the GRAPPA [Group for Research and Assessment of Psoriasis and Psoriatic Arthritis] domains, some of the common comorbidities you see associated with psoriatic arthritis.

Sheetal Desai, MD: Absolutely. Patients who present to rheumatology specialists usually have some form of arthritis, peripheral arthritis, whether it’s oligoarticular, polyarticular, asymmetric or symmetric. Often our patients have other areas of involvement, of their skin, of their nails, of inflammation where their tendons and ligaments attach to bone, spinal inflammation. Over the years I’m moving away from the term psoriatic arthritis and instead using the term psoriatic disease, to help remind us to incorporate the other domains that are involved.

GRAPPA does recommend assessments of all domains of involvement in our patients with psoriatic arthritis or psoriatic disease because often more than 1 domain is involved. There are 6 domains that are classically described. First is peripheral arthritis, which we’re comfortable with and we see a lot of. Skin involvement is seen in over 90% of our patients. Nail disease is seen in over 60% of our patients. Dactylitis, about 1 out of every 2 of our patients will have dactylitis; there is also enthesitis and axial inflammation. This is what we teach the fellows all the time, if you don’t go looking for it, you won’t find it. If you don’t take the socks and shoes off, you’re going to miss the dactylitis. If you don’t evaluate elbows and other areas of enthesitis, which are actually quite easy to evaluate on the physical examination, the patient may not even complain about it or realize that they have epicondylitis unless you do the exam maneuvers.

It’s important to know the domains because not all therapies are effective for each domain. Once we know the domains that are involved, then we can look at the multitude of therapeutics we have in this era available to us and assess which therapy might be best suited for the domains involved in those patients. We must not forget the comorbidities, as you mentioned. Common comorbidities that we see in psoriatic disease are psychiatric with anxiety and depression, increased rates of metabolic syndrome, increased rates of cardiovascular disease, paying attention to hypertension and dyslipidemia, and sometimes with young patients where their PCPs [primary care providers] may not be evaluating those conditions as often. But uveitis, I can’t tell you how many patients sometimes have inflammation of their eyes, and all of us probably feel the same, they go to see an ophthalmologist and they have no idea that that’s actually a part of their psoriatic disease and a comorbidity. Then there are inflammatory bowel disease or microscopic colitis.

A funny story I had recently is a scientist who was on etanercept for over 10 years for psoriatic arthritis, and when it stopped working as well, I switch him to adalimumab because the TNF [tumor necrosis factor] MOA [mechanism of action] worked so well in him. It was interesting, when he came back after being on adalimumab for several months, he said, “You know what, I just want to tell you something. It’s amazing that I used to have lactose intolerance, and it’s gone.” And I thought, oh my God, this poor gentleman had some degree of diarrhea and mucus in his stools that he attributed it to lactase intolerance, and it was likely some level of microscopic inflammation in his gut from his psoriatic disease. Unless we go looking and unless we talk to our patients and inquire about these comorbidities of all the domains of psoriatic disease, sometimes patients don’t even know that they’re all interrelated.

Anthony M. Turkiewicz, MD: Thank you, that’s a great point and sometimes, we don’t assume, but we think they know it’s part of it, but no. It’s a pivotal point to make, particularly when we’re educating our fellows and future doctors about this disease. Ana-Maria, if you don’t mind, would you briefly touch on some of the importance of trying to get an early, and sometimes this is the tough part, but an accurate diagnosis in psoriatic arthritis, and psoriasis as well, if you want to play the dermatologist. Can you walk through that a little bit for us?

Ana-Maria Orbai, MD, MHS: Yes. It’s very important. We know that psoriatic arthritis is underdiagnosed from multiple studies. We know that people with psoriatic arthritis will present a sizable proportion, up to 30%, of people with psoriasis. I sketched 3 big reasons that in my mind make diagnosing psoriatic arthritis so important.

The first is damage. The patients can acquire joint damage quickly, and in one study this was shown to be as soon as 6 months. Another aspect is suffering; patients are suffering. It’s known that prior to diagnosis, they experience stiffness, joint pain, fatigue. If they don’t have a cause for this, the sooner we find the explanation and they start the appropriate treatment, the better, because these things can improve. Third, it’s also access to treatment because oftentimes people with very little psoriasis who may just be taking topical treatments, if they have psoriatic arthritis and get the diagnosis quickly, they have access to treatments and they feel better, and the joint disease improves, we prevent damage, the skin disease also improves. We simplify everything if their diagnosis is clear as soon as possible.

Anthony M. Turkiewicz, MD: It’s convenient when it’s clear, and it’s not always the case though, obviously we know that.

Transcript Edited for Clarity