Allergic response produce histamines. These histamines will act on different areas of the body (eyes, throat, nose, gastrointestinal tract, skin or lungs) to produce symptoms of an allergic reaction. The allergic response is not limited to a certain amount of exposure. If the body is exposed to the allergen multiple times the immune system will react every time the allergen is present. The reason why people get allergies is not known. The allergens are not passed down through generations. It is believed if parents have allergies the child is more likely to be allergic to the same allergens. Some common symptoms include
Allergic transfusion reaction from a donor who has allergies, followed by antigen exposure. An allergic transfusion reaction is a type of transfusion reaction that is defined according to the Center for Disease Control (CDC) as: An allergic transfusion reaction is diagnosed if two or more of the following occur within 4 hours of cessation of transfusion: A probable diagnosis results if any one of the following occurring within 4 hours of cessation of transfusion: Treatment of an allergic transfusion reaction is to immediate stop the transfusion. If the only symptoms are mild (i.e., hives and itching), the patient may be treated with an