ITP is an acquired disorder of platelets: consider as either increased destruction or decreased production.
Classified as primary (a dx of exclusion) vs secondary.
Etiology: Caused by anti-platelet IgG directed against membrane proteins of the platelets.
Inciting events: infection vs immune alteration..
Incidence: highest in children, and increased incidence with increased age in adult.
DDx: drug-induced (heparin, quinine, sulfas, APAP, cimetidine, NSAIDs, ampicillin, piperacillin, vancomycin, GIIIPII inhibitors), chronic pancreatitis, sepsis with DIC, intracellular parasites, hypersplenism, nutritional deficiencies, EtOH use, pregnancy, pre-eclampsia/HELLP syndrome, cancer and myeloplastic disorders, thrombotic microangiopathies, APLA syndrome…and many, many more!
Hx: Ask about recent illness, new meds.
Clinical manifestations: bleeding only in 2/3 (serious <10K); petechiae; purpura (“wet purpura” – involvement of mucus membranes, a marker for more serious illness); epistaxis; severe hemorrhage (ICH, GI).
- Blood smear
- Rheum workup (ANA, RF) if symptoms suggestive
- H pylori if clinically suggested
- TSH if clinically suggested
- Bone marrow biopsy – if severe disease or no clear cause
ITP is NOT associated with abnormal hematologic morphology or coag abnormalities – if abnl RBCs, WBCs or coags, think something other than ITP!
- Hospitalize with severe bleeding or if platelets < 30K
- Heme consult
- Platelet transfusion
- Splenectomy for severe or recurrent disease
- Rituximab for severe disease