Aplastic anemia

Background

• Absence or decreased number of hematopoietic precursor cells → pancytopenia (anemia, thrombocytopenia, neutropenia)
• Causes:
  • Drug-induced (chloramphenicol, carbamazepine, valproic acid, phenytoin)
  • Viral infection (parvovirus B19, HIV, hepatitis), especially in patients with sickle cell disease or immunocompromise
  • Autoimmune
  • Congenital (Fanconi anemia)

Clinical Features

• Anemia
  • Weakness, fatigue, dyspnea
• Thrombocytopenia
  • Mucosal bleeding, petechiae
• Neutropenia
  • Recurrent infections, fever

Differential Diagnosis

Pancytopenia Causes

• Acute leukemia
• Myelodysplastic syndrome, myelofibrosis
• Aplastic anemia
• Infiltrative disease (e.g. lymphoma, multiple myeloma, metastatic carcinoma)
• Paroxysmal nocturnal hemoglobinuria
• Drugs/treatments (*drugs more commonly associated with pancytopenia)
  • Bone marrow irradiation*
  • Chemotherapy*(especially anthracyclines, methotrexate)
  • Anti-inflammatories (rituximab*, sulfasalazine*, colchicine, azathioprine, methotrexate)
  • Antimicrobials (chloramphenicol, ganciclovir, penicillin G*, dapsone*, quinine
  • Thiomides (propylthiouracil*, methimazole*, carbimazole)
  • Antipsychotics (clozapine*, olanzapine
  • Procainamide*
  • Cyclophosphamide
  • Antiepileptics ([[phenytoin], carbamazepine, phenobarbital)
• Infection
  • Tuberculosis
  • AIDS
  • Leishmaniasis, brucellosis, histoplasmosis.
  • Viruses causing aplastic anemia (viral hepatitis, Epstein-Barr virus, HIV, parvovirus B19)
• Systemic lupus erythematosus
• Hypersplenism
• Acute radiation syndrome

Evaluation

• CBC: pancytopenia
• Reticulocyte count: reduced or absent
• Peripheral smear

Management

• Transfuse PRBCs/platelets as needed for severe anemia/thrombocytopenia
• Antimicrobials if febrile and neutropenic

Disposition

• Generally admit

See Also

• Aplastic Crisis