An incomplete picture that can exacerbate the misdiagnosis/undiagnosed trend
A few years ago, my mom was reading medical journals and stumbled upon two newly discovered diseases: EDS and POTS. She was so excited -- it explained ALL of my symptoms. Never before had we found a diagnosis that actually encompassed everything. I can vividly remember standing excitedly on her back deck as she read aloud symptoms that I'd never considered before, like chronic back pain and getting a head rush every time I stand up. And the best news -- it had an easy at-home test to see if you might have it! So, she immediately set out to prove that this was what haunted me. She walked me through the Beighton test... and I failed. My score was too low. We ruled it out. I was crushed.
Here's the thing -- the Beighton Score is like grades in school; it's not as objective as you'd like. You could see three doctors and all three might give you different scores. How hard do you pull on the fingers? How do you tell for sure if an elbow or knee is hyperextending more than 10 degrees? My mom used the description in the journal to do the best she could, and it came out negative. Years later, at Dr. Clair Francomano's genetics clinic that specializes in EDS, they gave me a much higher score. More than this, they recognized that it's more than just those specific joints that matter. How loose is my neck? My metacarpals? Do my knees bow in, in addition to hyper-extending? How do I sit and stand comfortably? How's my breathing? Is my skin soft, stretchy, fragile, translucent, easily bruised, weirdly scarred... They even looked in my eyes with lights to see what color my sclera was. (BTW it was determined to be blue-grey -- what?? Last I checked my irises were blue-grey, and my sclera was white :-P)
EDS affects the whole body. So someone who doesn't have those particular joints loose may have other floppy joints. I have some incredibly tight places on my body (which is mostly deceptive muscle spasms), but my joints wiggle around with such ease that my PT sometimes jokes that she could nudge me with a feather and my joint would pop back into place. Normal PT manipulations are completely unnecessary (and in some cases dangerous) for me because every joint (including ribs, spine, etc) happily slips in and out of place at the slightest suggestion. Yet I didn't pass the Beighton Score because I can't touch my toes...
EDS is also a spectrum, so they may be loose but not as loose as the example photos in the manual. I have a friend who's been operating under an EDS diagnosis for awhile now, but went in to get an official diagnosis from a specialist, and came back negative. This person's elbows hyper-extend more than mine, but were deemed normal. More than this, though, everything else about their body looks EDS-like. I'm starting to notice, now that I've made several EDS friends/acquaintances, that we all have similar ways of sitting, standing, slouching, walking, etc. We wrap our legs one too many times around the other. We constantly find ways to rest our head in our hands and support our elbows on our knees, a counter, anything really. We can't stand or sit with equal weight on each leg, favoring one over the other or constantly switching between the two... there are a million quirks that are freakishly similar and common in the EDS community, that I'm now noticing aren't normal in the community at large. The specialists in Baltimore knew to look for these, but a PCP in Vermont, who just heard of this disease last year, is not able to make the call accurately with just the one simple test (plus family history).
And finally, EDS is an umbrella. There are many different types. Someone might epically fail the Beighton score but have a type that isn't hEDS (hypermobility-type EDS). From what I hear from patients who were originally told they don't have EDS, not many doctors around here seem to understand the different types.
I hope there will be more education for doctors to understand these nuances. Until that day, let's spread info patient-to-patient so that we can better educate our providers!