What is the Arthus reaction?

Question

Quizplus · Accepted Answer

The Arthus reaction is an acute local inflammatory response that occurs when an individual is given a second injection of a vaccine at the same site as the first injection. This immune complex-mediated reaction is named after French immunologist and bacteriologist, Jules Bordet and his student, Octave Gengou. It is characterized by pain, swelling, and redness at the injection site.

Answer: E
 The name given to skin wheals that occur during an allergy skin test is called the wheal-and-flare reaction. The wheal (a raised, circular area of skin) is due to the local release of histamine and other mediators from mast cells, leading to fluid accumulation in the skin. The flare (a surrounding redness) is due to the dilation of nearby blood vessels. While similar in appearance to the Arthus reaction, the wheal-and-flare reaction is a different type of immune response.

What Is the Arthus Reaction