A patient experiences anaphylactic shock following the administration of penicillin. What type of hypersensitivity reaction have they experienced?
Type I hypersensitivity reactions are mediated by IgE and occur rapidly. They include anaphylaxis, atopy, and asthmatic reactions.
Type I hypersensitivity reactions are mediated by IgE and occur rapidly. They include anaphylaxis, atopy, and asthmatic reactions.
Adverse drug reactions
An adverse drug reaction (ADR) describes harm associated with the use of a medication at a normal dose.
Adverse drug reactions are classified in the following way:-
Type A (pharmacological) can be predicted from the pharmacology of the drug involved. They are dose dependent and so are reversible on withdrawal of the drug.
Type B reactions (idiosyncratic) cannot be predicted from the known pharmacology of the drug. Type B reactions include allergic reactions.
Type A account for up to 80% of all ARDs.
Allergic reactions are subdivided by Gell and Coombs into:-
- Type I (IgE-mediated) reactions
- Type II (cytotoxic) reactions
- Type III (immune complex) reactions
- Type IV (cell mediated) reactions
