Possible delayed drug allergic reaction

Dear Ask The Doctor: I have taken Nabumetone 500 mg for the last couple of years off and on for shoulder pain. I took one 3 days agoo with no reaction then last night I took one under the exact same conditions (as close as I can tell) and had a serious reaction. I almost went to the Emergency Room. I started itching everywhere including my ears and throat then I started having trouble breathing and was sweating profusly. Next I got really sick to my stomach with vomiting and diaherra. This went on for about 30 minutes then I started feeling some better but was really weak. I made it to my bed but was still sick to my stomach for several hours afterward. My questions are: was this an allergic reaction to the medication and is it possible to develop and allergy to a medication in just a couple of days?

Dear Sandi: Drug reactions can occur immediately or as a delayed hypersensitivity allergic reaction. Antibiotics are the most common cause of allergic reaction, acute or delayed . Some allergic reactions cause serum sickness, which include fever, weakness, hives, joint pain and lymph node swelling. Although antibiotics are the drugs most often associated with delayed allergic reactions, any drug, including anticonvulsants, anesthetics, anti inflammatory, heart medications and preservatives, can cause a delayed allergic reaction. Rashes, itching and swelling, especially on the face, often accompany delayed drug reactions.