Chemical burn symptoms and conditions

I had intense stomach pain and diarrhea after one dose. Called Dr. on call, she said it was a separate virus from my UTI, and to continue doses. After last dose 2 days ago, I broke out in terrible hives that itch uncontrollably, and looks like I have a chemical burn behind my ears and scalp. I thought it was bedbugs from a hotel, until my eye swelled up. Went to Dr. today, she said it might be allergic reaction to the Macrobid, but was weird that it came after all doses. I have also been sleeping for the past two days with NO energy...

I am not sure if my side effect is from using Singulair or not. I just started taking the Singulair 10mg last Thursday only in the evenings. After 3 days my face was swollen to the point that I couldn't see. I went back to the doctor and he didn't think the Singulair had anything to do with it since he was treating me for a contact dermatitis chemical burn so I still continue to take the Singulair but the swelling hasn't gone away yet and it has been 3 more days. If anyone can shed some light on if this is a side effect from using Singulair it would be appreciated. I also am taking Xyzal in the mornings so therefore I am not sure if this is what caused my face to swell. Any replies would be appreciated.

After reading the first page of posts, I realize I am very lucky that some of the worse side effects. The first time I was prescribed Levaquin, 500 mg. for a UTI, I noticed that after one day my tongue tingled. The second day of treatment left me with a very sore tongue, as if someone had rubbed it with sandpaper. The next day, I got several large white blisters in the roof of my mouth, under my tongue and in the back of my throat. None of these symptoms were listed in the information pamphlet from the pharmacy. I called my doctor and he said it must have given my an oral yeast infection. He called in a prescriptin for Diflucan and Nystatin (an awful tasting orange liquid you have to swish in your mouth and swallow). It did not help. I went to him again so he could look at my mouth in person and I had lost 9 pounds in 6 days! I could not even stand to eat chicken noodle soup and I was living on water and jello. I am a diabetic who has to inject insulin, so my blood sugars were going crazy. He prescribed some other mouthwash and it took almost a whole week after finishing the Levaquin for all the blisters to get to a point where I could even brush my teeth again. I can't begin to describe the pain. I have UTI's a lot, but I made him promise never to prescribe Levaquin again. Well, two months ago, I got another UTI and tried 2 other meds that did not clear it up. He once again prescribed Levaquin, and now my mouth is inflamed and blistered. I don't think it is an oral yeast infection, because the symptoms are not the same. It feels more like some kind of chemical burn. Has anyone else had these symptoms? I just came back from a family reunion and I was miserable the whole time I was there.