justasking replied: "Hi! It is hard to understand allergic reactions. I have a family member with a similar problem. She developed allergy towards aspirin apparently out of the blue at 40. She cannot take a single drop because she'd go into anaphilactic shock (and this is a person that took aspirin normally before this specific day). Later, her reaction was diagnosed as allergy to NSAID (Non-Estheroid Anti Inflamatories Drugs) but a few years after she started developing sensibility to Ibuprofen and other fever/flu medications. It's a rollercoaster really. She's like the 0.0001% of the people that develops this and the doctors don't seem to know anything. She has learned to live with it, though. Relaxation makes up for a big part. Not being able to take a certain medication when you're not feeling ok requires putting a lot of your brain in healing yourself. There seems not to be a real explanation for it, or for what triggered the reactions. I can tell you that we've noticed that on periods with emotional situations, the allergy stresses. If the person is sad, blue, or even very very mad. A tranquil environment is a key in helping an allergic person gaining control. What I can say is: know yourself. You should have a physician you trust and you should definitely pay attention to what he/she says. However: try to understand your body yourself too, because not even a doctor is going to be able to do it better than you. Try to write down every time you have a reaction, and write what you were doing that day, what you felt, what you ate, what happened. You will be able to create theories and see patterns. Know them and learn from them, regardless of what the Doctors may say (we had a Doctor that say that people Allergic to NSAID do not develop allergies toward acetaminophen, and that actually send my family member acetaminophen for a fever... you can imagine what happened. We had doctors that have also said -in the beggining- that allergies are NOT developed at age 40... *sigh* They both recognized their mistakes a long time after.) Trust yourself! And learn about yourself, and do have a professional to go to :) Goodluck! EDIT: The second allergy developed for my family member was towards acetaminophen and its derivates. Ibuprophen is also a NSAID, if you have an allergy to aspirin and NSAIDs it's logic you won't be able to have ibuprophen ;) Goodluck!"