Fibromyalgia: Taxonomy

If you can’t tell the difference between an apple and an orange your study of fruit salad is not likely to yield useful results!

Let me start by saying that taxonomy was never my favorite area of study in medical school. That having been said I think that the newly proposed diagnostic guidelines for fibromyalgia while not perfect are an exciting development in the field.

 

By way of explanation I would like to recount some of my experiences as a first and second year medical student at Columbia P & S studying clinical psychiatry. As in many institution most of the students entered the school not really knowing what they wanted to do and most of us left he same way. In fact nearly half of us ended up in fields other than our stated plan at the beginning of internship. Not so the future psychiatrists. Virtually all of the students whose stated area of interest as first year students was psychiatry did in fact take their residencies in that field and the vast majority of those still practice it today. Furthermore it was almost as rare for someone whose stated interest was not psychiatry to transfer into the field. That having been said the faculty of psychiatry seemed to feel that there existed a credibility gap with those of us who were not aspiring “shrinks”. To that end they insisted, and I believe correctly, that although there were few physical findings that were of help and no laboratory tests that could be used, that psychiatric diagnosis should be as precise and reproducible as the diagnosis of fracture or congestive heart failure. The exact diagnostic criteria for mania, depression and schizophrenia were constantly drummed into our heads and I believe that by the end of our studies not even the future cardiac surgeons would have made an error in diagnosing the major psychotic illnesses.

 

In doing this the faculty made almost constant reference to a multivolume book known as DSM II, which stands for diagnostic and statistical manual edition 2. The fact that I believe that we are now using DSM V and awaiting DSM VI is I believe less important than the fact that letter “S” continues to be a vital part of the title. The psychiatric community has long known that without accurate and reproducible diagnosis, not only is effective treatment unlikely, but meaningful research is impossible. Not to belabor the point but if you can’t tell the difference between apples and oranges, your study of sweet edible things that grow on trees is not likely to make much headway. Likewise if you look at a bowl of fruit salad and can’t tell that it is a nonhomogeneous mixture of different fruit… Well you get the picture! But this is exactly the situation with fibromyalgia. The new criteria are important not because they are perfect, but simply, because they do a better job of separating the apples and the oranges. In fact our goal with this revision is actually to begin to separate the Macintoshes from the Granny Smiths.

 

Significant in the new proposal is its heavy reliance on history. The pain must be predominantly muscular, diffuse, aching in quality as well as variable in location and intensity. The 18 classical tender points have blessedly been eliminated. I suspect that the reason for this is that the patients in the research clinics like the patients in my office often fail to consult the medical books before they come into the office. My sorry lot of patient was always messing up failing to be tender where the book predicted and being tender almost everywhere else. Even more annoying was the inconsiderate patient who would show up with a great history for fibromyalgia and only 8 or 9 tender points. I ask you, “What is a conscientious hard working pain specialist to do?”

 

The fact is that the researchers have gone so far as to say that there are no positive findings that are truly indicative of fibromyalgia. This is not to say that a physical exam should not be done, but rather that the primary purpose is to exclude other conditions for which physical findings may be highly suggestive if not diagnostic.

 

In the same spirit many now recommend against routine blood test for standard rheumatologic markers. These markers are often positive at a low level. There is no consistent pattern and the values frequently change over time. In most cases the only consistent effect of this type of laboratory data is to cause many a clinician to go on a lengthy and expensive fishing trip looking for a rheumatologic condition that does not exist. The current recommendations are to order these tests only if a reasonable index of suspicion exists or if the ensuing clinical course is abnormal.

 

I think that with these new criteria we be able to focus our attention on the part of diagnostic process which is most accurate and reliable. Besides it is my distinct impression that most fibromyalgia patients would prefer to talk and leave the poking and prodding for other patients.

 

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