immune disorders
Anaphylactic Reactions
Causes of Anaphylactic Reactions
Anaphylactic reactions are most commonly caused by the following: Drugs (such as penicillin) Insect stings and animal venoms Certain foods (particularly eggs, seafood, and nuts) Latex But they can be caused by any allergen. Anaphylactoid reactions resemble anaphylactic reactions. However, anaphylactoid reactions, unlike anaphylactic reactions, may occur after the first exposure to a substance. Also, anaphylactoid reactions are not allergic reactions because immunoglobulin E (IgE), the class of Antibodies involved in allergic reactions, does not cause them. Rather, the reaction is caused directly by the substance. The most common triggers of anaphylactoid reactions include Iodine-containing substances that can be seen on x-rays ( Radiopaque Contrast Agents ) Aspirinand other nonsteroidal anti-inflammatory drugs (NSAIDs) Opioids Monoclonal antibodies (manufactured antibodies that target and suppress specific parts of the immune system) Exercise If possible, doctors avoid using radiopaque contrast agents in people who have anaphylactoid reactions to such agents. However, some disorders cannot be diagnosed without contrast agents. In such cases, doctors use contrast agents that are less likely to cause reactions. In addition, drugs that block anaphylactoid reactions, such asprednisoneanddiphenhydramine, are sometimes given before certain contrast agents are injected. 