Are all drug reactions caused by drug allergy?
Many people are sensitive to medications, but not all of these sensitivities are true allergic reactions. Some reactions to medications are well-known side effects. Among the most common side effects that people experience from medications are upset stomach, diarrhea, vomiting, fever and a skin reaction to sunlight called photosensitivity. These side effects are not the same as drug allergies. Side effects do not involve the immune system, and sometimes can be avoided by lowering the dose of the medication. Drug allergy reactions occur even after using small doses.
