Allergies

A drug allergy occurs when your immune system overreacts to something in a medicine. This causes an allergic reaction. Allergies are a very common problem, affecting at least 2 out of every 10 Americans. Allergies are an  abnormal response of the immune system. People who have allergies have  an immune system that reacts to a usually harmless substance in the environment.

This substance (pollen, mold, animal dander, etc.) is called an allergen. If a person is feeling like they have allergies, they may need to have an allergy test to figure out where the problem is coming from. Allergy testing will involve having skin or blood tests done to determine what substance or allergen is bringing on the problem. Skin tests are the most common because they are fast, reliable, and much less expensive than blood tests. However, any one of them can be used.

A drug allergy is a type of harmful, or adverse, drug reaction (such as a side effect or a reaction from taking more than one type of medicine). Because symptoms and treatments vary, it is important for your doctor to find out whether you have a drug allergy or another type of adverse reaction. Adverse reactions are usually not serious.

Although drug allergies can be life-threatening, most of them are mild, and symptoms go away within a few days after you stop using the medicine.