Suzie, I have previously read that many lupies are allergic to sulfa drugs. I know I am, and so is my daughter, who also has lupus.
BUT, I have to say this.... as someone with an allergy to sulfa drugs, and who has both lupus AND Lyme disease, the reaction that you're having does NOT sound at all like an allergic one.
It sounds like a classic Jarisch-Herxheimer reaction which is a feature of Lyme disease. When a person with Lyme is put on antibiotics they typically have a "herx" within 4 to 8 days.... during the herx, the symptoms get worse, because the spirochetal bacteria are dying and releasing toxins into your body. A herx can last a few days or even longer. Then you start feeling better for a few days, then (if you are still on the antibiotics), you'll have another herx. The spacing of the herx reactions is linked to the life cycle of the Lyme disease bacteria.
I'm REALLY familiar with herxes because I have Lyme and have been on many different antibiotics over the past two years. Currently I'm on 3 abx: Minocycline, Tindamax, and IV Merrem. I have a chest port into which I drip the Merrem solution 3 times a day at home. I have had Lyme since at least 2004, but wasn't diagnosed until 2010. That's why I'm still on antibiotics and probably still have a long road ahead.
Even if you've been tested before for Lyme and the results were negative, please visit the following URLs and read up on Lyme, just so that you can compare your symptoms and reactions. The current Lyme tests have many many false negatives; researchers have shown that they come up negative for about 50% of the people who actually DO have Lyme.
About the "herx": http://www.lymediseaseblog.com/jarisch-herxheimer-reaction-lyme-disease/
About Lyme and lupus symptom similarities and differences: http://lymediseaseguide.org/lyme-disease-lupus
The fact that Lyme disease can actually TRIGGER lupus!: http://lymemd.blogspot.com/2008/06/lyme-and-lupus.html
Also, there is a wonderful documentary on Lyme called "Under Our Skin" that you can watch for free at Hulu:
http://www.hulu.com/watch/268761/under-our-skin
Of course, I pray that you do NOT have Lyme!! It's a horrible disease and so difficult to treat by Stage 3 (I have Stage 3 chronic neuroLyme, it's in my central nervous system). But, given your current symptoms caused by a course of antibiotics, I think that you should look into the possibility, hon!
((((((((((hugs)))))))))
JoAnn