II. Definition

  1. Decreased Platelet Count below 100k to 150k

IV. History

  1. Family History of Thrombocytopenia
    1. Consider congenital Thrombocytopenia Causes
  2. Comorbid conditions
    1. Liver disease
    2. Heart Valve Replacement
  3. Pregnancy
    1. Gestational Thrombocytopenia
    2. Preeclampsia with HELLP Syndrome
  4. Social history
    1. Alcohol Abuse
  5. Recent viral infection
    1. Immune Thrombocytopenia (ITP) in children follows acute viral infection by days to weeks
    2. Cytomegalovirus (CMV)
    3. Epstein Barr Virus (EBV, Mononucleosis)
    4. Varicella Zoster Virus (VZV, Chicken Pox)
    5. Parvovirus B19
    6. HIV Infection
    7. Hepatitis C
  6. Tick Bite
    1. Anaplasmosis
    2. Babesiosis
    3. Rocky Mountain Spotted Fever
    4. Lyme Disease
  7. Recent international travel (especially tropical)
    1. Dengue Fever
    2. Malaria
    3. Rickettsial Disease
  8. Medications
    1. Drug-Induced Thrombocytopenia
    2. Heparin-Induced Thrombocytopenia
    3. Chemotherapy
    4. Radiation Therapy
    5. Immunizations (MMR, Varicella, H1N1 Influenza Vaccine)
    6. Transfusion
      1. Transfusion reaction
      2. Infection (Hepatitis C or HIV Infection)

V. Symptoms: Clues to Thrombocytopenia Causes

VI. Exam

  1. Complete exam to identify underlying cause (see below)
  2. Deep bleeding (e.g. hemarthrosis) suggest clotting disorder, not Thrombocytopenia
  3. Signs of bleeding (mucosal and superficial bleeding)
    1. Petechiae
    2. Purpura
    3. Gingival Bleeding
    4. Gastrointestinal Bleeding
    5. Urinary tract bleeding

VII. Signs: Clues to Thrombocytopenia Causes

  1. Rash
    1. Viral Exanthems (VZV, Parvovirus B19)
    2. Rickettsial infections
    3. Systemic Lupus Erythematosus
  2. Generalized Lymphadenopathy
    1. Viral Infections (e.g. CMV, EBV, HIV)
    2. Systemic Lupus Erythematosus
    3. Leukemia, Lymphoma and other hematiologic malignancies
  3. Hepatomegaly
    1. Chronic Liver Disease
    2. Leukemia
    3. Viral Infections (CMV, EBV, HCV)
  4. Splenomegaly
    1. Viral Infections (CMV, EBV)
  5. Neurologic findings
    1. Thrombotic Thrombocytopenic Purpura (TTP)
  6. Renal Failure
    1. Thrombotic Thrombocytopenic Purpura (TTP)
    2. Hemolytic Uremic Syndrome (HUS)

VIII. Causes

  1. See Thrombocytopenia Causes
  2. Categories of Thrombocytopenia
    1. Decreased platelet production (e.g. viral infection, medications, radiation, B12 Deficiency, marrow infiltration)
    2. Increased platelet destruction (e.g. ITP, TTP, HUS, DIC)
    3. Platelet loss
    4. Splenic Sequestration

IX. Labs: Platelet Count Interpretation

  1. Platelet Count 70,000 to 150,000 per uL
    1. Mild Thrombocytopenia
  2. Platelet Count 50,000 to 70,000 per uL
    1. Asymptomatic Moderate Thrombocytopenia
  3. Platelet Count 30,000 to 50,000 per uL
    1. Symptomatic Moderate Thrombocytopenia with excessive bleeding on Traumatic Injury
  4. Platelet Count 30,000 to 50,000 per uL
    1. Symptomatic Moderate Thrombocytopenia with excessive bleeding on Traumatic Injury
  5. Platelet Count 10,000 to 30,000 per uL
    1. Severe Thrombocytopenia with excessive bleeding with minimal Skin Trauma
  6. Platelet Count 5,000 to 10,000 per uL
    1. Severe Thrombocytopenia with risk of spontaneous bleeding, Bruising or Petechiae
    2. Spontaneous bleeding requiring intervention (e.g. Nasal Packing for Epistaxis) required in 42% of patients
  7. Platelet Count below 5,000 per uL
    1. Emergent Thrombocytopenia with high risk of major spontaneous bleeding (e.g. gastrointestinal tract, genitourinary tract)

X. Labs: Initial Evaluation of Thrombocytopenia

  1. Complete Blood Count (CBC)
  2. Basic chemistry panel (chem8)
    1. Evaluate for associated Renal Failure (e.g. TTP, HUS)
    2. Expand to comprehensive panel in Hemolysis
      1. Indirect Bilirubin increased in Hemolysis
      2. Serum Lactate Dehydrogenase and Haptoglobin increased in HUS and TTP
  3. Coagulation tests (INR, PTT, Fibrinogen)
    1. Normal in isolated Thrombocytopenia, ITP, TTP, HUS
    2. Prolonged in DIC, liver disease, Massive Transfusion and Trauma
    3. Fibrinogen is decreased in DIC and Trauma
  4. Peripheral Blood Smear
    1. See Platelet Morphology
    2. See Peripheral Blood Smear
    3. Schistocytes are present in DIC and Microangiopathic Hemolytic Anemia (TTP, HUS), but not ITP
    4. Consider Parasite stains (Tick Borne Illness, Malaria)
    5. Hemolysis will raise Indirect Bilirubin
  5. Platelet Count
    1. Rule-out Pseudothrombocytopenia
      1. Review Peripheral Smear to evaluate for clumping (Pseudothrombocytopenia)
      2. Repeat Platelet Count in non-EDTA Anticoagulant (citrate, blue tube)
    2. Repeat Platelet Count timing (adjust based on chronicity, stability and bleeding complications)
      1. Repeat immediately for developing bleeding complications
      2. Repeat in days to 1 week if Platelet Count <50,000 per uL
      3. Repeat in 2 weeks if Platelet Count <100,000 per uL
      4. Repeat in 4 weeks if Platelet Count <150,000 per uL

XI. Management: General Approach

  1. Red Flag Findings accompanying Thrombocytopenia indicating Hematology Referral
    1. Leukopenia or Leukocytosis
    2. Anemia
    3. Peripheral Blood Smear abnormalities
    4. Symptomatic Thrombocytopenia with Bleeding Diathesis, Petechiae, Purpura or Ecchymosis
    5. Platelet Count <50,000 per uL (or persistently below 100,000 per uL on repeat testing)
  2. Conditions requiring emergent management
    1. Heparin Induced Thrombocytopenia (HIT)
    2. Thrombotic Thrombocytopenic Purpura (TTP)
    3. Hemolytic Uremic Syndrome (HUS)
    4. Preeclampsia with HELLP Syndrome
  3. Disposition home
    1. Isolated Thrombocytopenia >30,000/mm3 without signs of bleeding in children
    2. Isolated Thrombocytopenia >30,000 to 50,000/mm3 without signs of bleeding in adults
    3. No serious cause suspected of Thrombocytopenia (i.e. not HUS, TTP, HIT, DIC)
      1. Less severe causes include ITP and Drug induced Thrombocytopenia
    4. Reliable patient or family
      1. No NSAIDS
      2. Follow activity restrictions as below
  4. Management precautions
    1. Avoid platalet transfusion in Hemolytic Uremic Syndrome, Thrombotic Thrombocytopenic Purpura
    2. Avoid Corticosteroids in suspected malignancy (until cancer evaluation and staging)

XII. Management: Activity and Procedure Limitations

  1. Platelet Count >50,000 per uL
    1. No limitations to activity or procedures
    2. Use caution in Collision Sports with Thrombocytopenia
    3. Most surgical procedures can be perfromed safely at this Platelet Count
    4. Epidural Anesthesia is safe at 50,000 per uL, but >100,000 per uL is preferred
  2. Platelet Count >20,000 per uL
    1. Bone Marrow Biopsy, bronchoscopy and endoscopy can be performed
  3. Platelet Count <10,000 per uL
    1. Avoid Collision Sports and other activities with risk of Traumatic Injury

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Ontology: Thrombocytopenia (C0040034)

Definition (MSHCZE) Nedostatek krevních destiček trombocytů v krvi v důsledku jejich malé tvorby např. při útlumu kostní dřeně, leukemii nebo jejich zvýšeného zániku např. v rámci autoimunitního onemocnění, při němž jsou destičky ničeny vlastními protilátkami, ITP. Další možností je zvýšené ukládání při hypersplenismu či spotřeba při DIC konzumpční t. Výrazný nedostatek vede ke spontánnímu krvácení z dásní, sliznic, do kůže aj. (cit. Velký lékařský slovník online, 2012 http://lekarske.slovniky.cz/ )
Definition (NCI_NCI-GLOSS) A condition in which there is a lower-than-normal number of platelets in the blood. It may result in easy bruising and excessive bleeding from wounds or bleeding in mucous membranes and other tissues.
Definition (NCI_CTCAE) A finding based on laboratory test results that indicate a decrease in number of platelets in a blood specimen.
Definition (NCI) A condition in which there is an abnormally small number of platelets in the circulating blood.
Definition (CSP) decrease in the number of blood platelets.
Definition (MSH) A subnormal level of BLOOD PLATELETS.
Concepts Finding (T033)
MSH D013921
ICD9 287.5
ICD10 D69.6
SnomedCT 165556002, 70786006, 191326009, 142969008, 154827000, 302215000, 415116008
English Thrombocytopenia, Thrombocytopenias, Thrombopenia, Thrombopenias, THROMBOCYTOPENIA, THROMBOPENIA, Thrombocytopenia, unspecified, thrombocytopenia (diagnosis), thrombocytopenia, Thrombocytopaenia, Thrombocytopenia NOS, Thrombocytopenia [Disease/Finding], reduced platelet count, Thrombocytopenia NOS (disorder), Thrombocytopenia (disorder), Platelet count decreased, Thrombocytopenic Disorder, Thrombocytopenic disorder, Thrombocytopenic disorder (disorder), thrombopenia, Thrombocytopenia, NOS, Platelet count below reference range (finding), Platelet count below reference range, thrombocytopaenia
French THROMBOPENIE, THROMBOCYTOPENIE, Thrombocytopénie non précisée, Thrombocytopénies, Hypoplaquettose, Thrombocytopénie, Thrombopénie
Portuguese TROMBOCITOPENIA, TROMBOPENIA, Trombocitopenia NE, Trombocitopenias, Trombocitopenia, Trombopenia
Spanish TROMBOCITOPENIA, TROMBOPENIA, Trombocitopenia no especificada, recuento plaquetario inferior al valor de referencia (hallazgo), recuento plaquetario por debajo del intervalo de referencia, recuento plaquetario inferior al valor de referencia, recuento plaquetario por debajo del intervalo de referencia (hallazgo), recuento plaquetario por debajo del rango de referencia (hallazgo), recuento plaquetario por debajo del límite inferior de referencia, recuento plaquetario por debajo del rango de referencia, trombocitopenia (trastorno), trombocitopenia, SAI (trastorno), plaquetopenia, SAI, trombocitopenia, SAI, trombopenia, Thrombocytopenia NOS, trastorno trombocitopénico (trastorno), trastorno trombocitopénico, trombocitopenia, Trombocitopenias, Trombocitopenia, Trombopenia
German THROMBOZYTOPENIE, Thrombozytopenie, unsepzifisch, THROMBOPENIE, Thrombozytopenie, nicht naeher bezeichnet, Thrombozytopenien, Thrombopenie, Thrombozytopenie
Italian Trombocitopenie, Trombocitopenia NAS, Trombocitopenia, Piastrinopenia, Trombopenia
Dutch trombocytopenie, niet-gespecificeerd, trombopenie, Trombocytopenie, niet gespecificeerd, trombocytopenie, trombocytopenieën, Trombocytopenie, Trombopenie
Japanese 詳細不明の血小板減少症, ショウサイフメイノケッショウバンゲンショウショウ, ケッショウバンゲンショウショウ, 血小板減少症, 血小板減少, 栓球減少症, 栓球減少
Swedish Trombocytopeni
Czech trombocytopenie, Trombopenie, Trombocytopenie, blíže neurčená, Snížené počty trombocytů, Trombocytopenie, trombopenie
Finnish Trombosytopenia
Russian TROMBOTSITOPENIIA, TROMBOPENIIA, ТРОМБОПЕНИЯ, ТРОМБОЦИТОПЕНИЯ
Korean 상세불명의 혈소판감소증
Croatian TROMBOCITOPENIJA
Polish Małopłytkowość
Hungarian Thrombocytopeniák, Thrombocytopaenia, thrombocytopenia, thrombocytopenia, nem meghatározott, Thrombopenia
Norwegian Trombocytopeni, Trombopeni