How are serum sickness and arthus reaction similar?

Serum sickness and Arthus reaction are both classified as type III hypersensitivity reactions. This type of hypersensitivity occurs when immune complexes formed from the binding of antigen and antibody deposit in tissues, leading to an inflammatory response.

In serum sickness, immune complexes are formed following the administration of certain proteins, often from animal serum, which the body recognizes as foreign. This leads to symptoms that may include fever, rash, and arthritis.

The Arthus reaction is a localized manifestation that occurs when an immune complex forms in response to an intradermal injection of an antigen, resulting in localized inflammation and tissue damage, often observed as swelling and redness at the site of injection.

Both conditions exemplify the effects of immune complexes in causing tissue injury and inflammation, thereby illustrating the detrimental consequences of type III hypersensitivity. Understanding this classification helps in diagnosing and managing these conditions appropriately.