Hummingbird, There's a resource in the "sticky post" ( = permanent post") at the top of the thread list, the thread called "Answers to tests results questions". Navigate around there to find info about Lupus & Skin.
Lupus skin rashes can "cross subsets". One rash predominates in a lupus type, but other rashes can spring up, too. For example, someone with SLE (systemic lupus) has higher odds of having a malar rash, but could ALSO get discoid rashes, or SCLE rashes, or etc. Likewise with someone with the SCLE subset of lupus: she is most likely to have an SCLE annular or psoriasiform rash, but is also "eligible" for discoid and malar.
So, because of this potential for rashes to sometimes "cross subsets", a lupus rash *alone* doesn't define what type of lupus one has. A rash, once proven to be a LUPUS rash, says that the person has some kind of lupus, but not WHICH kind of lupus.
WHICH KIND OF LUPUS ONE HAS: Someone is said to have SYSTEMIC lupus when she meets "4" or more of the "4 of 11" criteria for SLE. (There's a "sticky post" on this, too.) The criteria don't have to exist simultaneously: they should be counted over one's LIFETIME, making very thorough medical history very important.
IF LESS THAN 4 criteria: A person may stop at one or two; a good example of this would be someone with DLE (discoid LE). People with the SCLE subset (subactute cutaneous LE) often have "4" or more, but typically not the worst possible ones (kidney & CNS are thought to be less likely).
So the REAL TRICK is for a doctor to determine if someone with less than "4" has only DLE or maybe SCLE---or whether that person is on the way to developing systemic lupus (SLE). Like Glojer says, sometimes a dr. will consider this fuzzy area to be generic "connective tissue disease" until more things either crop up, or DON'T crop up.
There are subgroups in CTD, too, for example, UCTD (undifferentiated CTD) and MCTD (mixed CTD). Each has a set of definitions, too.
Plus other *non-lupus* autoimmunes can have skin issues, e.g., dermatomyositis.
BACK TO WHAT YOUR BIOPSY MEANS: Good question! Do you know what kind of test(s) were done? Was it a "lupus band test", of both sun-exposed and non-sun-exposed skin? Or just one punch of a rashy area, subjected to microscopic exam, then maybe immunofluorescent stain tests as well?
WHAT DOES YOUR RASH LOOK LIKE? Did you even have a rash? (Just curious.)
OTHER AUTHORS: There are several authors with good lupus hardcovers, available in a lot of libraries & bookstores. Both include skin info. One author is Dr. Daniel Wallace. The other is Dr. Robert Lahita.
Sorry I can't answer your question, not really (plus I'm just a patient, too, like all of us here). FYI, I had years of what was *finally* Dx'ed as the annular form of SCLE rash, on upper arms & torso. I never had a malar rash. I was ANA-negative, anemic, elevated ESR; plus I had fevers, fatigue, weight loss, hair breakage, migraines, GI & urinary problems, neuro-like tingling, photosensitivity, etc. My local drs. & specialists would NOT make ANY call, would not treat me, and never even told me that a CTD was suspected.
When my weight went to about 102 (at 5'8"), I blew sky-high & took myself to a teaching hospital rheumie. Along with the dermatopathologist he sent me to for a final biopsy, he Dx'ed me with the SCLE "subset". I scored a "4" in the "4 of 11", and I finally tested positive for anti-Ro. I've been on Plaquenil ever since, for 6 years. I must avoid sun like the plague
I hope there's something useful to you in this too-long post! It's so hard to condense. I hope you post more soon. Meanwhile, take good care. Sincerely, Vee