Is Psoriatic Arthritis underdiagnosed?

We all know the numbers - it is estimated that only 10-30% of people with Psoriasis will be diagnosed with Psoriatic Arthritis. But is the low rate of co-incidence because people with P(soriasis) don't usually develop Ps(oriatic) A(rthritis), or because many people with P don't realize they also have PsA? I tend to think the latter, and I think research is starting to back me up.

A recent Canadian research survey on people with Psoriasis (not Psoriatic Arthritis), called the SKIN study (cute) suggests that PsA could be widely underdiagnosed. The article I read about the study states:

The SKIN survey reveals that half of all respondents [with Psoriasis] reported that they had developed joint pain or stiffness, but only 18 per cent of these respondents had ever received a diagnosis of psoriatic arthritis.

and...

Respondents reporting no psoriatic arthritis diagnosis indicated that they experienced stiffness in the knees, shoulders and hips (48 per cent), followed by pain or stiffness in the finger joints (38 per cent) and toe joints (23 per cent).

Underdiagnosis concerns me for two reasons - firstly, of course, I don't want anyone else to experience the pain I experience. But secondly, fewer people diagnosed with PsA means the research community will be less likely to study PsA.

A while back I wrote about the lack of research and basic information about Psoriatic Arthritis, as compared to Rheumatoid Arthritis and Psoriasis. Here's the link.

Here's my point: fewer scholarly articles on PsA will lead doctors to make fewer diagnoses, AND, the lack of PsA diagnoses certainly has an effect on how much research is undertaken.

So if you're out there with P, and think you have PsA, please consider getting a definitive diagnosis.

You know what they say about the squeaky wheel, after all. I'm up for some grease (and I'm not talking another ointment).

A new twist on the doctor/patient relationship

Imagine what it would be like if your doctor really knew what you were thinking. Imagine if, almost daily, she knew how you were doing: which days were bad and which were good, when your joints were hurting like fire and when you felt like a million bucks.

I got another "call" from my rheumatologist last week... and as it turns out, she knows things I haven't told her. She knows when I'm hurting, and when I'm exhausted. She knows that the dactylitis in my toe is killing me, and that last month I was so wiped out from a flare that I lost my creative fire. And she's concerned, because she thinks I should be doing better with my psoriatic arthritis.

The crazy thing is, until she called, I thought she thought I was doing just fine.

During the past 2 weeks, we both realized that the person she sees in her office for 15 minutes every 2 months is different from the person I am during the rest of my life. What changed?

She started reading my blog. Faithfully.

(An aside: Hi Dr. _____, I hope you're having a good day! See you for my infusion next month!).

It was a revelation to us that we had so deeply miscommunicated about what our goals were for my health. As a consequence, we have both done some thinking and talking about how we view each other, as "patient" and "doctor", and how we view other "patients" and "doctors" in our lives.

I don't think I gloss things over with my doctors. I tell the truth about where my pain is, and how bad. And she doesn't think she glosses over things in her visits (and as you all know, I think she walks on water).

But somehow, during the our conversations, we miscommuncated about what we were shooting for. She talks about "remission" - and to her that means symptom-free, a normal life. To me "remission" means better. She talks about "better" and thinks symptom-free, normal life. To me "better" means I can get down the stairs a bit faster than this summer.

I've become so accustomed to pain that I realize that I don't think about the little things anymore. I don't sweat the small stuff. I've become numb to the days when my hands are so stiff I can't type for an hour in the morning, or my hips ache when I bend down to pick up a Lego. At least I can ride my bike, right? So to me I'm "better".

But to her, I'm not.

She told me she has gotten sad thinking about her other patients that she doesn't really know as well as she's gotten to know me, because of my writing, and that she can't help as well as she's trying to help me. She told me she's been thinking hard about how she practices medicine.

I'll save our new treatment plan for another blog post (My hands aren't working so well today, Dr. _____).

But before I stop, I just want to say to all of you patients and physicians out there: sweat the small stuff. Don't give up on getting to "better", and even more important, make sure you both agree on what "better" looks like. Make sure you both have the same goal. Talk.

And write your own blog. It works.

Are autoimmune diseases connected? I think yes!

A fellow Psoriatic Arthritis patient asked me to explain whether (and why) if someone has one autoimmune disease, they are more likely to get a second one. For example, in my case, is there some reason other than chance that I have both Psoriatic Arthritis and Celiac Disease?

To tell the truth... if I could answer that question I could win the Nobel prize and run a whole lot of people out of work. The immune system is incredibly complex, and a layperson like me can only skim the surface of understanding it.

Here's what I do know, however, after doing some sleuthing.

Yes, autoimmune diseases come in multi-packs, like underwear from Target. If you have one, you're likely to get two or three. This is called co-morbidity, btw. Just last month, an article in the American Journal of Epidemiology discussed some researchers' attempts to demonstrate autoimmune co-morbidity. The authors used public records to see how often rheumatoid arthritis, multiple sclerosis, autoimmune thyroiditis and insulin-dependent diabetes mellitus were present in the same individual. And they found that there was a high co-occurrence between rheumatoid arthritis, insulin-dependent diabetes mellitus and autoimmune thyroiditis. BUT... they found that there was an inverse relationship between RA and MS - which means that if you had one, you were LESS likely to have the other! Go figure. This reverse relationship does speak to a relationship... but what kind of relationship?

Dr. Noel Rose wrote an essay called The Common Thread discussing the etiology (the cause) of autoimmune diseases and the need for more research on the links between them. You can find the paper on the American Autoimmune Related Diseases Association website. Dr. Rose states:

Autoimmunity is an etiology: it is a cause of disease. Anatomically, autoimmune disease is very diverse; and that's why we see specialists in so many areas of medicine studying autoimmunity. They may be rheumatologists who are interested in joints; they may be dermatologists who are interested in skin; they may be cardiologists who are interested in the heart; they may be gastroenterologists who are interested in the gastrointestinal tract. But the common etiology for all of these disease--for Crohn's disease of the gut; for lupus of the skin; for rheumatoid arthritis of the joint--the common etiology that brings together all of these diseases is autoimmunity.

Dr. Rose doesn't necessarily say that one disease can cause another, but that's not what we're talking about. We're talking about whether they occur at the same time, and whether autoimmune diseases are all just one disorder with multiple symptoms. It does make sense that if you are having a problem with your immune system in general, that the problem won't always limit itself to one organ or region, but can be systemic. But how do we prove that all of these autoimmune diseases are related, or perhaps one underlying disease?

Here's one data point that suggests a connection: many different autoimmune diseases can be treated by the same medication - and I'm not just talking about diseases that look similar, like psoriatic arthritis and rheumatoid arthritis. For example, my husband and I could get Abbott labs to give us a bulk discount - Humira treats PsA and Crohn's Disease. Humira is a TNF-alpha blocker - and both of our diseases can be linked to an excess of TNF-alpha. On the other hand, so far, Humira doesn't seem to treat every auto-immune disease.

In their book "The Autoimmune Connection" Rita Baron-Faust, Jill P. Buyon, M.D. hypothesize about some of the reasons autoimmune diseases may co-occur, or may perhaps be one disease with multiple symptoms. They say:

While autoimmune diseases may target different areas of the body, the genes that affect immune responses may be the same. For example, genes that govern cytokines may have a mutation that causes too many inflammatory molecules to be released. Defective genes common to autoimmune diseases may also affect the way T-cells are programmed to recognize antigens, the number of receptors they carry, the number of T-cells with a faulty memory, or how many defective T-cells are eliminated.

Researchers are now trying to demonstrate, on a genetic level, that many autoimmune diseases are related. A group of researchers looked across 42 separate studies of 11 autoimmune diseases to see if they could find underlying genetic links. They found that several diseases shared some common genetic fingerprints (the HLA region of chromosome 6 lit up for many autoimmune diseases, as did many parts of chromosome 16). On the other hand, there were several genes that seemed to be involved with only one disease. This is from the Feb 2009 issue of the European Journal of Human Genetics - you can read the abstract here.

So, ok, what do we know about autoimmune co-morbidity? What do we think? Here's what I've learned:

• Many autoimmune diseases are likely to co-occur in the same person, but some aren't.
• Many researchers think that separate autoimmune diseases have a shared etiology, or cause, and may possibly be one disease. Some evidence supports this, but some doesn't.
  
• Many autoimmune diseases share similar genetic links, but not in all cases.

What does this mean? Folks, it means that we need more research. And of course, this means we need more funding for research. If you haven't yet, find some way to support research on your disease(s), or autoimmune disease in general. Go to the NPF website, or the AARDA website. Do something, and keep talking.

It also speaks to something I've discussed before in my blog - the fact that humans' compulsions to put things in boxes - to categorize - may limit how we understand disease. Maybe autoimmune diseases are all just one disease... maybe they aren't, but they just share a lot of qualities or root causes. Do the diagnostics get in the way of knowledge? I think yes, sometimes. Perhaps a more holistic approach to research, diagnosis, and treatment would help use understand these symptoms (not diseases) better.

It also means I have a lot more to learn before I ever attempt to write a logical post about this topic again. This is complicated stuff.

Are psoriasis and psoriatic arthritis different diseases?

Maryanne Kazanis, a research fellow at Harvard and a med student, presented a paper in Japan last summer suggesting that psoriasis and psoriatic arthritis could possibly be different diseases. Check this out:

Support for the one-disease concept comes from the observation that arthritis occurs more frequently in patients with cutaneous psoriasis than in nonpsoriatic controls.

On the other hand, the fact that a drug such as cydosporine is effective for the skin manifestations of psoriasis but provides little benefit for psoriatic joint symptoms has caused many physicians to lean toward the view that psoriasis and psoriatic arthritis are two diseases, albeit possibly sharing some immunopathogenetic elements, Ms. Kazanis said.

The heart of the article goes on to discuss Kazanis' research, which demonstrates that different diseases co-occur with psoriasis vs. psoriatic arthritis. The article also highlights some of the measurement issues in this study. It's worth a read...

My two cents? I'm again struck with the similarities between psoriatic arthritis and rheumatoid arthritis, both in symptoms and the types of treatment that work. We really are just beginning to learn about these diseases, and anything is possible. What if psoriatic arthritis and rheumatoid arthritis are the same disease, with a few different symptoms? What if rheumatoid factor is just a symptom that some folks develop? And... what if psoriasis is a different disease that occurs a lot in people with PsA/RA type arthritis? What do you think?

I really gotta go get my M.D. This armchair speculation is making me woozy.

A rose by any other name... would be something else?

The New York Times had a fascinating article in their magazine this weekend about the Undiagnosed Diseases Program sponsored by the N.I.H. The article focused on a 31 year old woman named Summer Stiers in declining health, who has spent the last 20 being undiagnosed or misdiagnosed by well-intentioned physicians. She was frequently misdiagnosed with autoimmune conditions, because her symptoms just scream "autoimmune".

The article followed her disease progression, and her experiences in Bethesda, MD being examined by a constellation of specialists from the N.I.H.

There were countless fascinating aspects of this article - I recommend you take the time to read through it. However, what stood out most to me was the difficulty physicians have in making accurate diagnoses, even now, with all of our tools and experience. The article highlights how the N.I.H. is trying to advance knowledge about both specific illnesses and the diagnostic process through the Undiagnosed Diseases Program, and it brings home how complicated the jobs of physicians AND patients are when addressed a complicated array of symptoms.

A few weeks ago I wrote about how fractured and fragmented our current of system of diagnostics are, and the article on Summer Stiers included a great discussion of this problem. Forgive the long quote - this is from page 5 - but I found this so interesting, esp in light of diagnostics in the field of autoimmunology (italics mine):

The balkanization of medicine accounts for an increasingly constrained approach to diagnosis — an approach that... is defined by a specialist’s focused knowledge rather than by some broader understanding of the patient. “This is partly because of how medicine is taught — how it has to be taught,” said Kathryn Montgomery, professor of medical humanities and bioethics and of medicine at the Northwestern University medical school in Chicago, when we spoke by telephone. “Doctors get educated to solve problems in their own terms. They’ve got only a certain set of information and experience at their disposal.”

Few physicians are trained to look at the patient as a whole, Montgomery says, with the exception of generalists like internists and pediatricians. ...

But the problem is not just overspecialization, Montgomery says; it’s the complex nature of diagnosis itself, and the difficulty of trying to teach the process in medical school. Because diagnosis involves so many intersecting and often incompatible parts, medical students have traditionally been taught to do opposite things at once when they meet a new patient: suspend judgment, but form an initial impression; look for a single diagnosis to explain all symptoms, but watch for co-morbidities; avoid the anecdotal, but pay attention to stories; expect the diagnosis to be a common disease, but don’t forget the rare ones. This dissonant approach was recently modified in some medical schools, according to Montgomery, with students now taught to begin with a “working diagnosis” that they refine as they accumulate data that either confirm or refute their first guess. But while the working-diagnosis method might clarify some things, Montgomery worries about what might be lost: a sense, as she wrote in her 2006 book, “How Doctors Think: Clinical Judgment and the Practice of Medicine,” of an alternative pathway. Because of the inherent contradictions traditionally taught in medical school, she wrote, new doctors have been able to achieve “a certain balance, a consciousness that, no matter which way they may work through a diagnosis, there is another way.”

As patients, we see similar contradictions in our roles of finding the right doctors. Do I find an older doctor... someone with lots of clinical experience? Or should I turn to someone who is fairly new out of school, who has fresh knowledge on the most modern techniques and research? Do I find a generalist or a specialist? Do I look to someone who is alternative in their approach, or have two separate doctors, one representing the "western" approach and one representing an alternative approach? When meeting a doctor for the first time, do I tell them my whole complicated history, or just focus on the day's issues?

This makes me more and more convinced that I am my own boss re: my health (see "I'm canceling everybody"). Doctors, by the very fact that they are human with limited brain-space, are fallible. We have to be our own agents, and rely on our doctors as we would rely on consultants. We have to be our own Chief Information Officers.