An allergic reaction occurs when your body attacks a foreign, and typically harmless, substance. Learn about common allergens ...

Bee, wasp, yellow jacket, hornet, and fire ant are the insect stings that most often trigger allergic reactions. But most people aren't allergic to insect stings and may mistake a normal sting ...

Drug hypersensitivity reactions are drug reactions which are unpredictable. They result from an interaction between a drug substance and the immune system of a hypersensitive person. Hypersensitivity ...

Either allergic-type reactions or contrast-induced nephropathy may occur after administration of radiographic contrast media. These are entirely different entities with distinct pathophysiologies.

Transfusion reactions are medical complications that arise after a blood transfusion. They may occur during the transfusion (known as acute) or weeks after it (delayed). They're further classified ...

A recent case has shown that, the body can have an unexpected systemic immune response after a Botox procedure. This reaction ...