Hypersensitivity reactions should be subdivided into immune-mediated (or immuno-allergic), and non-immune-mediated reactions, hence the term “pseudoallergic.” Whereas immune-mediated reactions involve the specific recognition of the offending agent by the immune system and immunological memory, non-immune-mediated reactions reflect the release of some mediators involved in immune-mediated reactions through strictly non-immunological mechanisms (Farnam et al. 2012). The antique term “anaphylactoid” has often been used to describe acute adverse reactions mimicking anaphylactic reactions, the mechanism of which was not understood.
Pseudoallergic Versus Immuno-allergic Reactions
The clinical features of pseudoallergic reactions often mimic acute immune-allergic reactions, at least to some extent, which accounts for frequent inaccurate diagnosis. In sharp contrast to immune-mediated reactions, non-immune-mediated reactions...