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Granulocytopenia is a topic covered in the 5-Minute Emergency Consult.

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  • A significant decrease in the number of granulocytes in the peripheral blood.
  • 3 classes of granulocytes:
    • Neutrophils or polymorphonuclear (PMN) cells and bands
    • Eosinophils
    • Basophils
  • As PMN cells predominate, the term neutropenia is often used interchangeably with granulocytopenia, as almost all granulocytopenic patients are neutropenic.
  • Granulocytes are a key component of the innate immune system.
  • The clinical risks resulting from granulocytopenia are best defined by the level of the absolute neutrophil count (ANC):
    • ANC = WBC × percentage (PMN + bands)
    • Modern automated instruments often calculate and report ANC.
  • Neutropenia: ANC <1,500 cells/mm3:
    • Mild: Between 1,000 and 1,500
    • Moderate: Between 500 and 1,000
    • Severe: <500
    • Agranulocytosis: <100
    • Patients with a count <1,000 that has recently or rapidly fallen are at greater risk for infection than those with a count <500 but rising.
    • Patients with myelodysplastic syndromes should be considered granulocytopenic with higher counts because of defective neutrophils.
  • 4 basic mechanisms cause granulocytopenia:
    • Decreased production
    • Ineffective granulopoiesis
    • Shift of circulating PMN cells to vascular endothelium
    • Enhanced peripheral destruction.
  • Mortality of fever and neutropenia is as high as 50% if untreated:
    • Mortality correlates with the duration and severity of the neutropenia and the time elapsed until the 1st dose of antibiotics.
  • 21% of patients with cancer and neutropenic fever develop serious complications.

Pediatric Considerations
  • Newborn infants have a physiologically elevated ANC in the 1st few days of life and may be granulocytopenic with levels >1,500/μL.
  • Children >3 mo without underlying immunodeficiency or a central venous catheter unexpectedly found to have isolated moderate neutropenia are not at high risk of serious bacterial infection.


  • Most common in patients undergoing myelosuppressive drug therapy or radiation treatment for neoplasms. Most common 5–10 days after chemo.
  • Adverse reaction to drugs is the 2nd most common cause:
    • Excludes cytotoxic drugs and requires at least 4 wk of administration prior to the onset of granulocytopenia
    • Discontinuation usually results with correction within 30 days.
    • Drugs with the highest risk:
      • Antipsychotic: Clozapine
      • Antibiotic: Sulfasalazine
      • Antithyroid: Thioamides
    • Antiplatelet agents
    • Antiepileptic drugs
    • NSAIDs
  • Drugs that suppress the bone marrow:
    • Methotrexate
    • Cyclophosphamide
    • Colchicine
    • Azathioprine
    • Ganciclovir
  • Chemicals
  • Bacterial infections:
    • Typhoid
    • Shigella enteritis
    • Brucellosis
    • Tularemia
    • Tuberculosis
  • Parasitic infections:
    • Kala azar
    • Malaria
  • Rickettsial infections:
    • Rickettsialpox
    • Ehrlichiosis
    • Rocky Mountain spotted fever
  • Viral infections
  • Postinfectious neutropenia:
    • Most severe and protracted following HIV, hepatitis B, and Epstein–Barr viral infections
  • Immune-related:
    • Primary immune neutropenia:
      • Due to antineutrophil antibodies
    • Crohn's disease
    • Systemic lupus erythematosus
    • Rheumatoid arthritis
    • Goodpasture disease
    • Wegener granulomatosis
    • Thymoma
    • Compliment activation
  • Bone marrow infiltration
  • Transfusion reaction
  • Alcoholism
  • Vitamin deficiency (B12/folate/copper)
  • Chronic idiopathic neutropenia
  • Pure white cell aplasia

Pediatric Considerations
  • Congenital neutropenia:
    • Neutropenia with abnormal immunoglobulins
    • Reticular dysgenesis
    • Severe congenital neutropenia or Kostmann syndrome
    • Cyclic neutropenia
  • Chronic benign neutropenia
  • Neonatal isoimmune neutropenia
  • Shwachman–Diamond syndrome
  • Cartilage–hair hypoplasia
  • Dyskeratosis congenita
  • Barth syndrome
  • Chédiak–Higashi syndrome
  • Myelokathexis
  • Lazy leukocyte syndrome
  • Cohen syndrome
  • Hermansky–Pudlak syndrome type 2

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Rosen, Peter, et al., editors. "Granulocytopenia." 5-Minute Emergency Consult, 5th ed., Lippincott Williams & Wilkins, 2016. Emergency Central, emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307332/all/Granulocytopenia.
Granulocytopenia. In: Rosen P, Shayne P, Barkin AZ, et al, eds. 5-Minute Emergency Consult. 5th ed. Lippincott Williams & Wilkins; 2016. https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307332/all/Granulocytopenia. Accessed April 24, 2019.
Granulocytopenia. (2016). In Rosen, P., Shayne, P., Barkin, A. Z., Wolfe, R. E., Hayden, S. R., Barkin, R. M., & Schaider, J. J. (Eds.), 5-Minute Emergency Consult. Available from https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307332/all/Granulocytopenia
Granulocytopenia [Internet]. In: Rosen P, Shayne P, Barkin AZ, Wolfe RE, Hayden SR, Barkin RM, Schaider JJ, editors. 5-Minute Emergency Consult. Lippincott Williams & Wilkins; 2016. [cited 2019 April 24]. Available from: https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307332/all/Granulocytopenia.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Granulocytopenia ID - 307332 ED - Rosen,Peter, ED - Shayne,Philip, ED - Barkin,Adam Z, ED - Wolfe,Richard E, ED - Hayden,Stephen R, ED - Barkin,Roger M, ED - Schaider,Jeffrey J, BT - 5-Minute Emergency Consult UR - https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307332/all/Granulocytopenia PB - Lippincott Williams & Wilkins ET - 5 DB - Emergency Central DP - Unbound Medicine ER -