I seem to have developed these horizontal white lines under my nails, which I'm sure weren't there a year ago.
By "horizontal" do you mean from one side of the nail bed to the other? Horizontal ridges
can definitely be part of the clinical picture of psoriasis/PsA. Horizontal ridges can also be something called Beau's lines, which can occur after injury or serious illness. A quick search turned up this page which describes white horizontal lines (not ridges) as "Muehrcke's nails" which "are usually seen when blood protein levels are low." (Disclaimer: even though it is "Yahoo voices" it is written by an MD though who knows if it's truly accurate...) http://voices.yahoo.com/what-causes-white-fingernail-lines-6214686.html?cat=69
I have no pitting in my nails, but I have very deep, long, verticle ridges.
Vertical ridges (cuticle to nail tip) are common & benign, and aren't an SpA symptom: http://www.mayoclinic.com/health/nails/AN00591
Good source of general info on various nail abnormalities:http://www.nlm.nih.gov/medlineplus/ency/article/003247.htm
After all these years, my spondyloarthropathy still hasn't chosen to go down one specific road. At this point, I've decided that it likes being a diverse and unpredictable traveler.
SpA doesn't need a "path." Knowing it's SpA and treating it as such is sufficient. As Lizzie & others have said, obtaining a more granular diagnosis will have minimal impact on your treatment options (except from an insurance payment perspective, for some.)
the more I read about mis-diagnoses (or total void of any), the more I shake my head. In reflection it seems the doctors I've encountered were avoiding the consideration of AS like it was the plague!
Part of the problem is the persistent use of the term "AS" which makes SpA diagnosis even harder for those of us who do not meet the modified NY criteria but still have other signs/symptoms/history that fit the SpA picture and nothing else. My own rheumy never uses terms like spondylitis, spondyloarthropathy, SpA, undiff spondy, etc. He has ONLY referenced AS and so he seems to be quite puzzled over what is wrong with me since I obviously don't have RA and do not meet the AS criteria.
At my annual visit yesterday he even "demoted" my diagnosis code from "unspecified inflammatory spondylopathy" to "back pain." I must admit that I feel insulted by this. It's not that he doesn't believe me - I know that he does. I've seen him for years and my complaints (pain location and level) are very consistent. Plus he doesn't prescribe me any opioids or other drugs that could be abused (I have a pain doc for that) so he knows I'm not a drug seeker. He even let me try 3 different anti-TNFs though he was dubious they'd help (of course, when they didn't, that did not help my cause with him, either.) He also knows I have dutifully gone to PT when he suggested it, and a 4 week steroid taper took away ALL my pain. AND I am going back next week to see him to discuss a plan for trying all the stuff that is left (immunomodulators like 6-MP, Plaquenil, MTX) in the hope that maybe something - or some combination of things - will work for me.
So I know he wants to help me, which makes his stubborn refusal to concede I am afflicted by SpA and nothing else all the more hurtful - and personal.