In response to the latest post:
I have been taking Singulair for the past week and have also broken out into hives. I have hives on my back, shoulders, chest, and sporadic bumps on other parts of my body. I thought it was just part of my seasonal allergies (albeit a very severe allergic reaction), but also suspected Singulair. I'm glad I Google searched the side effects and found this. I'm going to discontinue immediately.