Arthus reaction

Definition

The Arthus reaction is a type of local hypersensitivity reaction that occurs when an antigen is injected into the skin, leading to severe inflammation. It is mediated by immune complexes and typically involves IgG antibodies.

5 Must Know Facts For Your Next Test

1. The Arthus reaction is a Type III hypersensitivity reaction.
2. It involves the formation of immune complexes between circulating antibodies and injected antigens.
3. Symptoms include localized redness, swelling, and tissue damage at the site of injection.
4. This reaction usually occurs within hours after exposure to the antigen.
5. It can be experimentally induced in laboratory animals to study immune complex diseases.

Related terms

Type III Hypersensitivity: An immune response caused by antigen-antibody complexes that deposit in tissues and lead to inflammation.

Immune Complex: A molecule formed from the binding of multiple antigens to antibodies, often leading to inflammation.

IgG Antibodies: A class of antibodies that play a crucial role in secondary immune responses and are involved in many hypersensitivity reactions.