Passive Cutaneous Anaphylaxis

**Definition:** An evanescent cutaneous reaction occurring when antibody is injected into a local area on the skin and antigen is subsequently injected intravenously along with a dye. The dye makes the rapidly occurring capillary dilatation and increased vascular permeability readily visible by leakage into the reaction site. PCA is a sensitive reaction for detecting very small quantities of antibodies and is also a method for studying the mechanisms of immediate hypersensitivity.

**Tree numbers:** - E01.370.225.812.871.600 - E05.200.812.871.600 - E05.478.594.890.600 - G12.122.754

**Synonyms:** - PCA - Anaphylaxis, Passive Cutaneous