RA or PsA: What’s the Difference?

Red-hot, swollen joints lead to excruciating pain.  Patients, writhing in agony, phone their doctors for help.  For the lucky, a quick diagnosis is made:  rheumatoid arthritis.  The luck is in the speedy diagnosis, not in the unfortunate diagnosis itself.

Often the diagnosis is unclear.  Doctors aren’t sure what the problem is, or even if there is a problem.  Alas, it’s not unusual for busy doctors to give hurting people in this situation the brush-off with, “It’s all in your head.”  If  your disease doesn’t match the pattern described in textbooks (atypical presentation), it’s hard for doctors to recognize.  Diagnosis of autoimmune disease can take years.

Even when a doctor determines that autoimmunity is the culprit, it might not be clear exactly which disease is causing the problem.  Many have very similar symptoms. Fortunately, arthritic diseases caused by a faulty immune system respond to similar medicines.  In order to get insurance to cover treatment, a diagnostic-label is sometimes affixed despite the uncertainty.  Over time, the uncertainty is forgotten and the tentative label takes on a life of its own.  Maybe it doesn’t matter.  After all, at least the patient gets treated.

Then again, maybe accurate diagnosis wherein different diseases are clearly distinguished would lead to better data about which medicines would be most likely to help a given patient.  It’s maddening to suffer through years of trial-and-error hoping to find effective treatment. When rheumatologists evaluate a new patient with autoimmune arthritis, one question is, “Is this rheumatoid arthritis, or is it psoriatic arthritis (or is it something else entirely)?”  Keys they look for are 1) nail involvement, and 2) skin psoriasis.  There is no nail involvement in RA.  In PsA, 80% of patients have nail symptoms such as ridges, grooves, and/or pitting.  Psoriatic finger/toenails can thicken instead of growing longer, sometimes even crumbling or falling off.  The problem with using nails as diagnostic criteria is that, according to the National Psoriasis Foundation, 20% of PsA patients do not have nail symptoms.  I propose that looking for ridged nails without asking about ridged nails is an exercise in futility, since people with unsightly nails might address the issue.  Furthermore, according to the American College of Rheumatology, “Psoriatic arthritis can occur in people without skin psoriasis, particularly in those who have relatives with psoriasis.”  In fact, in juveniles, up to half of PsA patients experience arthritis symptoms before there is any skin involvement.  Obviously we have a problem.

Dr. Irwin Lim, rheumatologist, writes:

Many patients labeled as having “Seronegative Rheumatoid Arthritis” or “Seronegative Inflammatory Arthritis” may have Psoriatic Arthritis.

In two short video clips, he explains more:

Not all patients with the diagnosis of psoriatic arthritis will have skin manifestations. Sometimes the diagnosis is made from a collection of other symptoms and signs, and a positive family history. Sometimes the rash actually occurs years after the development of psoriatic arthritis. So, it’s definitely possible to have psoriatic arthritis without the skin psoriasis.

Psoriatic arthritis can be very difficult to diagnose. It really does require the doctors to have a high index of suspicion. In patients who already have psoriasis affecting the skin or nails, the diagnosis is much easier because most people would think about it. But, sometimes, the symptoms can be quite vague. So many people have back pain, and it’s often explained away. In addition, joints aches and pains are common in the community, and sometimes the link with psoriatic arthritis is not put together. So, typically the diagnosis is made by an experienced physician taking into account the history, the examination, and the clinical context.

He is not alone in his views.  Doctors Jaya Philipose, MD and Atul Deodhar, MD write

The diagnosis of psoriatic arthritis (PsA) often is missed, partly because patients may present with inflammatory spinal pain, tendinitis, enthesitis, or dactylitis rather than a “true arthritis.”

It’s important to note that the rheumatologist is looking for clues at a single moment in time. In contrast, the patient knows a lifetime’s worth of history. If patients know the types of patterns that doctors are looking for, we can better provide the information that our doctors need to make an accurate diagnosis.

Usually doctors looking at family history are only interested in first-degree blood relatives:  parents, children, and full-siblings.  When considering psoriasis, though, doctors are also interested in second-degree relatives:  grandparents, grandchildren, half-siblings, aunts, uncles, nieces, and nephews.  Contact family members and ask.  Don’t just ask about psoriasis.  Ask about rashes and flakey skin.  Ask about severe dandruff — on the elbows and knees as well as on the scalp (not everyone is going to see a doctor for a diagnosis of those flakes).  See if  you can find a pattern.  Patterns can help your doctor make a diagnosis.

Following is a chart comparing some of the similarities and differences of RA & PsA:

PsAvsRA

For further reading:

Dr. Google

You don’t have to read medblogs for long to learn that doctors do not appreciate it when patients research symptoms on the internet, then show up for an appointment with printouts.  Irritating the person who’s supposed to be helping us isn’t a good idea, so it makes sense to not take printouts to appointments.

That doesn’t mean patients can’t read reliable websites (Up-to-Date and Mayo Clinic are good places to start).  It just means that we ought not tell the doctor how to do his/her job.  It goes over much better if we don’t provide a diagnosis; patients provide symptoms and let the doctor come up with a diagnosis.  At least that’s what the medblogs say.

But what if the doctor’s diagnosis is wrong?

I’ve written before about the red sores that my rheumatologist and family physician thought might be psoriasis, but my dermatologist diagnosed as nummular dermatitis.  Those &#%$ spots show up if I miss one of my cimzia/mtx injections, and take a couple months to go away — unless I dig into my stash of prednisone, in which case they are gone in a couple weeks.  It’s obviously something related to the RA, but what?

Well, recently I googled another symptom (completely unrelated, I thought) that has plagued me for well over a year.  I find it bothersome, but not something I’d dream of making an appointment about. It certainly would never come up in the course of conversation at the doctor’s office.  However, in reading the differential diagnosis for that symptom, up popped vasculitis.  Really?  Others with RA have mentioned vasculitis, but I didn’t know much about it, so started reading.  The articles include photographs of red sores, mainly on the legs, that look very much like what my dermatologist said is something completely different. Reading about vasculitis is frightening, so I hope that’s not what this is.  But I need to know.

At my next appointment, I think I will ask if it’s possible that those red blotches all over my skin could be vasculitis instead of nummular dermatitis. The trick is finding out without annoying my doctors.

Endurance

Perturbed, frustrated, aggravated, irritated, upset, disturbed, annoyed, bothered, discouraged, disheartened, dispirited, downcast, dejected…  I need a bigger thesaurus.

When I left rheumy #1 for rheumy #2, I was clear about what I wanted:

  • a doctor with whom I had good rapport
  • a doctor in private practice, not owned by a hospital
  • a doctor who saw patients without shuffling them aside to a PA

For a few years things were going well.  Unfortunately, about a year ago my doctor’s practice sold out.

Once they were owned by a hospital, things changed.  First thing to go was the excellent front office staff.  They were moved elsewhere within the system and replaced by lemon-suckers who just seem to be going through the motions.  Next my doctor’s MA (who always managed to process prescription refills within one day) disappeared; it now takes five days to approve refills and there’s a different MA every time I’m there.

To add insult to injury, the hospital brought in PAs.  Instead of seeing my private MD, I now see a hospital-employed PA.  The PA might be a nice person, might be competent after learning to do joint exams without causing pain, might be a lot of things. What the PA is not is the doctor with whom I established a relationship.  I feel betrayed.

Now the office is calling to move my appointment.  It seems that the hospital system has decided to open another clinic at another one of their hospitals.  My choice is to drive an extra 30 minutes or move my appointment to a different day.

I want out, but there doesn’t seem to be any point in finding a new doctor right now, since whoever I find could eventually sell out, leaving me right back in the same position.  Instead, I will show up for appointments as rarely as possible so that my prescription refills will be approved.  My youngest child is twelve; in six years he’ll head to college, and four years after that he should graduate.  That means I just have to deal with this ten more years before we can retire and move away.  If I can get away with follow-up visits every six months, that means I only have to go in twenty more times.  By then, I expect the medical profession to have undergone significant changes, and finding a new rheumy will likely be a completely different situation than it is now.

Twenty might sound like a lot, but I remember how many appointments I had the first few years after I was diagnosed. Twenty is nothing.  Although I was unhappy about things when I started this post, I actually feel better now.  I can endure twenty visits.