That is no longer completely true. At least some cases of auto-immune disorders are caused by, essentially, a bored immune system. A newly developed treatment for some such disorders is to actually give the patient parasites (I would assume that viral diseases and bacteria would also be viable options, but I haven't heard of either being used). That gives the immune system something to do other than attacking the body. There has been some success in a cases of diabetes (Type I or Type I-Like forms of it), Irritable Bowel Syndrome, and fibromyalgia. However, the full implications of this discovery are still being investigated.
The new era of medicine is about patient investment in the treatment process. You doctor doesn't know everything s/he needs to know, so it is always a good idea to try to research your condition yourself. Wikipedia and WebMD are fine places to start for some diseases, but if you want cutting edge information, I'd recommend searching PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) and PubMed Central (http://www.pubmedcentral.nih.gov/) every now and then. Those are the National Institute of Health's repositories for all biomedical journal publications resulting at least partially from government funding. In short, there is more information on Lupus in those two repositories than your doctor has probably read.
Thank you for the great suggestion, but I actually have done vast amounts of research on my condition.
(I was very lucky in that I went to a medical magnet school for highschool, which opened my eyes to the great amount of resources out there! Students had full access to all sorts of online databases for research projects.) Right now, I'm inclined to say there is no known cause because there isn't a definitive, medically-agreed upon answer to what causes auto-immune conditions. I've heard the theory you mentioned as well as many others, including one that believes autoimmune conditions are caused by a chronic infection, which is therein treated by pulsed doses of antibiotics over a long period of time. (Marshall Protocol, you might have heard of it!) Until there is a definitive answer from the scientific community - and not just theories and treatments with some evidence of success inside test groups - I'm inclined to say that there really is no answer, at least not yet. There certainly have been some wonderful developments, though, that's for sure.
As for the "bored immune system" theory, I'm not a doctor or a researcher, so my opinion here is completely worhtless, but I don't think that was the case for me. Before I was diagnosed, even still after, I was the type who got sick extremely frequently, mostly with bacterial bronchitis. I usually was in the doctor's office with it seven to eight times a year for most of my life. My immune system has always been pretty busy, haha!
I've even had bronchitis and a lupus flare at the same time, but I don't know if my symptoms were alleviated because of it; I had a large dose of prednisone at the time, which would have taken care of both the liver inflammation and the bronchial inflammation. It's an interesting theory nonetheless, and I can't wait to see how it plays out!
Also, just as a side note, I don't believe fibromyalgia is an autoimmune condition. Autoimmune conditions usually require certain antibodies present in the blood, and from what I've gathered, they've typically found none of these antibodies in a primary fibromyalgia patients. (Interestingly enough, though, fibromyalgia tends to be a secondary condition to a lot of AI disorders. Even in myself, I have a much higher number of painful pressure points when my disease is active. 14/18, compared to 3/18 when in remission.)
As for Texas and humidity, I understand! I'm a Texan myself.
You know it's bad when your jeans start sticking to your legs.
