As we all know, psoriatic arthritis (PsA) is often a challenging disease to diagnose. Physical exam findings are not often definitive. Lab results are rarely much help. Even the patient history may not always give us the clear answers we’re looking for.

But as confusing as it can be for us as healthcare providers, think about what our patients are going through. Here they are in the rheumatology office, sometimes after being given a variety of other potential diagnoses from other providers, and we throw at them yet another possible explanation. How are they supposed to know who is right and who is wrong? Where can they go to help them make the right decisions?

That’s was the dilemma that one of my current patients, Susan, had to suffer through for several years.

Susan initially came to our practice at age 62 complaining of osteoarthritis that she thought was associated with an injury to her sternoclavicular joint suffered on the golf course. She also complained of mild, intermittent pain in her shoulders, knees, hips, and hands. My colleague who evaluated her felt that these latter symptoms were age appropriate, which they certainly can be. An x-ray and MRI of the sternoclavicular joint was unremarkable. A standard lab panel did not show anything abnormal. Based on our nonspecific findings, my colleague suggested to Susan that she start with a daily NSAID. That helped with her sternoclavicular joint pain for a short time, but its effects wore off within a month or two.

She then received a series of multiple injections, including corticosteroids, platelet-rich plasma, and acupuncture. The corticosteroids typically helped for approximately 2-3 months, while the plasma injections and acupuncture didn’t help at all. Again, we were left searching for answers.

I became involved in Susan’s care in 2016 not long after she turned 64 years old. After our initial visit, I ordered an MRI to re-evaluate her sternoclavicular joint. Here are my notes from that assessment:

“Nonetheless, this was the breakthrough I needed to convince Susan that a diagnosis of PsA was indeed likely.”

Mild subchondral edema in the proximal left sternum at the sternoclavicular joint, likely representing mild degenerative disease. There is no evidence of dislocation at the sternoclavicular joint. Remainder of physical: visualized osseous structures (remain normal), cortical bone marrow signal intensity without evidence of fracture, trabecular bone injury, or dislocation. Incidental findings in her left shoulder showed: Superior labral tear and calcified tendinopathy of the rotator cuff.

These findings were what initially raised my suspicions of a possible diagnosis of PsA. Subcondral edema generally refers to changes within the bone marrow that is often associated with degenerative disease, although it can also occur in patients with PsA.¹ Because Susan did not report any injury to her left shoulder, the labral tear and calcified tendinopathy of the rotator cuff were likely due to inflammatory arthritis.

At this point, Susan’s quality of life had begun to diminish. She was no longer playing golf, previously her favorite pastime. She said she was achy all over. She was not sleeping well. She showed some signs of depression, was fatigued, and suffered from irritable bowel syndrome and insomnia. On top of everything else, she developed fibromyalgia.

As you can expect in a motivated patient like this, Susan was running to every specialist she could think of to try to figure out what was going on—the gastroenterologist, the neurologist, the orthopedist, and her primary care provider. No one could figure out the right answer to all of her issues. Not long after our first meeting, I explained to Susan that, based on her imaging, prior history, and current symptoms, I felt she had three overlapping conditions—psoriatic arthritis, fibromyalgia, and osteoarthritis. We talked about any potential family history of any of these conditions. Susan said there was none. I asked her if she had ever noticed any signs of psoriasis, such as scaly patches or dry, cracked skin. Again, she said no.

Susan was in complete denial about the possibility of having an autoimmune condition. “My labs have always been normal!” she told me. When I showed Susan her most recent MRI and noted the changes I had seen compared to prior imaging studies, she still wasn’t convinced. Her other providers had hammered into her that her general soreness was entirely age related, and my belief otherwise wasn’t enough to override their opinions.

I was, fortunately, able to convince Susan that she had fibromyalgia. She had done some reading online and felt that her symptoms at least fit that diagnosis. She started on duloxetine 60 mg, which helped with her general fatigue. We added topical diclofenac and gabapentin to help her sleep. These also helped Susan’s fibromyalgia-related symptoms but did not touch her inflammatory pain.

Each time she came in for a visit, I talked with Susan about my feelings that she had PsA that was slowly but steadily progressing. In addition to her persistent sternoclavicular pain, her other joints were starting to hurt more. She had swelling and stiffness in her hands. Her general pain and stiffness had spread to the peripheral phalanges and distal interphalangeal joints, which are both commonly impacted in patients with PsA. Her nails started to show signs of pitting, another classic sign of PsA.

It was at this point, approximately 18 months after I first met with Susan, she finally had an “A-ha!” moment, remembering that she had had lesions on her scalp diagnosed as psoriasis many years ago. She had taken clobetasol for a few months, which worked to resolve the patchy areas, but hadn’t needed the topical medication for many years. Nonetheless, this was the breakthrough I needed to convince Susan that a diagnosis of PsA was indeed likely.

I spent a considerable amount of time during our next visit discussing initial treatment options, running through the benefits and risks of methotrexate (MTX) and biologic therapy. Susan chose a conservative route initially—which is fine—and began on MTX 15 mg once weekly, along with folic acid 1 mg daily. Since she did not have any axial involvement, I was comfortable with this plan.

Six weeks later, Susan was back for her initial re-assessment. Her lab results remained unremarkable. She told me that she felt “some improvement” in her general levels of pain and did not have any side effects to MTX. We decided to up her dose of MTX to 20 mg once weekly. At her next visit, Susan said she felt about “80% improvement,” which was good, but I still tried my best to persuade her that we could do more. Susan was quite anxious about potential medication-related side effects, as many of our patients are, so we spent quite a bit of time reviewing efficacy and safety data of potential options. She finally agreed to a trial of subcutaneous ustekinumab 45 mg in addition to the MTX and folic acid.

This turned out to be a life-changing decision. Her pain dissolved entirely. It had been so long since Susan had had a pain-free morning that she told me, “I barely remembered what that feels like!” She was able to once again take up golf, as well as some of her other hobbies. After a year on ustekinumab, Susan’s disease remained stable, and we were able to wean her off of MTX.

Susan is now 69 years old and continues to do great on her current medication regimen. She’s incredibly grateful that she’s been able to regain control of her life, and she thanks me every time she comes in for not giving up despite her initial obstinance. I thank her as well for always listening even when she didn’t agree with me.

It’s always a bright spot in our days as healthcare providers when we get to see patients whose lives have been positively impacted through our guidance and insight. We don’t always break through our patients’ defenses on the first visit (or even the second or third!), and it can be frustrating when we feel like we’re banging our head against the wall over and over, but it is with patients like Susan that I remember why persistence can pay off in the long run.

Reference

1. Sudoł-Szopińska I, Pracoń G. Diagnostic imaging of psoriatic arthritis. Part II: magnetic resonance imaging and ultrasonography. J Ultrason. 2016;16(65):163-174.

AUTHOR PROFILE: Nancy Eisenberger, MSN, APRN, FNP-C Nancy Eisenberger, MSN, APRN, FNP-C, is a nurse practitioner at Arthritis, Rheumatic and Back Disease Associates in Voorhees, NJ, and a member at large on the Rheumatology Nurses Society Board of Directors.

Participants will receive 2.75 hours of continuing nursing contact hours by completing the education in our course: Rheumatology Nurse Practice: The Challenges of Diagnosing Psoriatic Arthritis