Immune-mediated heparin-induced thrombocytopenia

This code identifies a severe adverse drug reaction characterized by a significant drop in platelet count due to antibodies formed against heparin-platelet factor 4 complexes. It is an immune-mediated condition that can lead to both thrombotic and hemorrhagic complications.

Assign this code when documentation clearly indicates a diagnosis of immune-mediated heparin-induced thrombocytopenia, often confirmed by laboratory tests such as the HIT antibody assay. This typically occurs in patients who have received heparin therapy and subsequently develop thrombocytopenia.

• Distinguish from non-immune mediated thrombocytopenia or other drug-induced thrombocytopenias.
• Ensure documentation specifies "immune-mediated" to support this specific code.
• Code any associated thrombotic or hemorrhagic complications separately.