There are two types of HIT. Type 1 is the most common form and is a nonimmune-mediated reaction in which platelet count will drop soon after exposure to heparin (can be as early as the first day of treatment) but will return to normal once the heparin is discontinued. Type 2 is an immune- or antibody-mediated reaction that takes 5-14 days after the start of heparin treatment to manifest. If a patient has been exposed to heparin and developed antibodies in the past, however, type 2 HIT can develop in the first day of treatment. The patient can develop hypercoagulability with high morbidity (10%) and mortality (20%).
D75.82 – Heparin induced thrombocytopenia (HIT)
73397007 – Heparin-induced thrombocytopenia
Differential Diagnosis & Pitfalls
Drug Reaction Data