2. THROMBOCYTOPENIA
Thrombocytopenia is defined as a platelet count
below 150 x 109/L as the lower limit of normal.
However, platelet counts between 100 and 150
109/L do not necessarily indicate disease if they
have been stable for more than 6 months.
3. THROMBOCYTOPENIA
Clinically significant spontaneous bleeding does not
usually occur until the platelet count is less than 10-
20 x 109/L.
However, the presence of thrombocytopenia can
aggravate surgical or traumatic bleeding or prevent
the administration of effective treatment for several
conditions (eg, antiviral therapy for chronic hepatitis C
virus infection or cancer chemotherapy, elective
surgery)
4. ETIOLOGY
Primary immune thrombocytopenia (primary ITP).
Drug-induced immune thrombocytopenia:
Heparin-induced thrombocytopenia (HIT) - in this condition, anti-platelet
antibodies activate platelets resulting in thrombosis (both arterial and
venous)
Quinine
Sulfonamides, ampicillin, vancomycin, piperacillin
Acetaminophen, ibuprofen, naproxen
Cimetidine
Glycoprotein IIb/IIIa inhibitors
Other over the counter remedies, supplements, foods like African bean,
sesame seeds, walnuts) and beverages (herbal teas and cranberry juice)
Drug-induced non-immune thrombocytopenia. Drugs like valproic
acid, daptomycin, linezolid cause thrombocytopenia by dose-
dependent suppression of platelet production.
5. Infections:
Viral: HIV, hepatitis C, Ebstein-Barr virus, parvovirus, mumps, varicella, rubella,
Zika viral infections
Sepsis causes bone marrow suppression.
Helicobacter pylori
Leptospirosis, brucellosis, anaplasmosis, and other tick-borne infections
Malaria, babesiosis intracellular parasite infections are associated with
thrombocytopenia and hemolytic anemia
Hypersplenism due to chronic liver disease
Chronic alcohol abuse
Nutrient deficiencies (folate, vitamin B12, copper)
Autoimmune disorders like SLE, RA associated with secondary ITP
Pregnancy. Mild thrombocytopenia presents in gestational
thrombocytopenia; moderate-severe thrombocytopenia can occur in
preeclampsia and HELLP (hemolysis, elevated liver enzymes, low
platelet count) syndrome
6. Myelodysplasia
Malignancy: cancer with chronic DIC, cancer with marrow
suppression (leukemia, lymphoma, solid tumors)
Paroxysmal nocturnal hemoglobinuria (PNH)
Thrombotic microangiopathy (TMA)
Thrombotic thrombocytopenic purpura (TTP), a condition
manifested by fever, renal failure, thrombocytopenia,
microangiopathic hemolytic anemia with or without neurologic
manifestations
A hemolytic uremic syndrome (HUS) caused by Shiga toxin-
producing organism (E. coli and Shigella), seen in children.
Drug-induced TMA: quinine, specific chemotherapy agents
Antiphospholipid antibody syndrome
Aplastic anemia
Inherited thrombocytopenia. Often seen in children, rare in
adults