serum sickness

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A hypersensitive reaction to the administration of a foreign serum, characterized by fever, swelling, skin rash, and enlargement of the lymph nodes.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An allergylike reaction to proteins in antiserum derived from animal sources.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a delayed allergic reaction to the injection of an antiserum caused by an antibody reaction to an antigen in the donor serum