Many of my fellow rheumatologists are not aware of how common this problem is, especially in women. In undifferentiated spondyloarthropathy, pain may be the only complaint, and the diagnostically helpful genetic marker HLA-B27, seen in 70% to 95% of people with the other spondyloarthropathies, is commonly absent. Thus the increased difficulty in making a diagnosis. 

If an individual has long-standing, persistant low back pain that came on gradually (commonly radiating to the buttocks) before the age of 45, and generalized body stiffness that is most severe upon wakening in the morning and gets better with exercise rather than worse, undifferentiated spondyloarthropathy should be considered. 

A history of pain and swelling in the feet and hands, and especially heel pain, is a further flashing warning beacon. Failure to recognize this particular form of a treatable arthritis in women is most probably the result of the long taught fact, now recognized as false, that AS and other spondyloarthropathies, are rare in women. 

My personal observation is that many individuals with diffuse muscle aches and pains, present without measurable laboratory or x-ray abnormalities, who have been told they have fibromyalgia, may truly have undifferentiated spondyloarthropathy. My impression has been supported by a large recent study published in the American Journal of Medicine. Another recent study in the Archives of Internal Medicine reports that misdiagnosis is common in women. It is important to make a correct diagnosis. 

An excellent response to aggressive anti-inflammatory therapy can be seen in undifferentiated spondyloarthropathy. This contrasts to the often futile use of nonsteroidal anti-inflammatory drugs in fibromyalgia. The long-term prognosis of AS and the family of related diseases is certainly much better now than before aggressive anti-inflammatory therapy was encouraged, and the consensus is that the course is even better in women. 

One of the few rheumatology textbooks available in 1960 listed the male-to-female ratio as 9:1, and in 1972 the most widely read text taught "4:1 to 8:1"! Only in 1989 did a standard textbook acknowledge that AS was "almost as frequent in females as in males." Think of how many physicians who learned from these books are still under the misconception that this "family of diseases" is predominantly made up of males! In 1979, when I first recognized how common ankylosing spondylitis was in many of my female patients, I asked 13 of them, all HLA-B27 positive, to appear at a medical Grand Rounds at our hospital, as seen in the above photo. Most had been told that they had "fibromyalgia" or that they were "anxious and depressed." The title of this teaching session, possibly better accepted in 1979 than 1998, was "A Bevy of B27 Beauties."
 
This article was from the Spring 1998 issue of the Spondylitis Plus Quarterly.