Aplastic Anemia

1. Epidemiology
   1. Median age of onset: 25 years
2. Presentation: Symptoms
   1. Fatigue
   2. Fever
3. Causes: Acquired
   1. Idiopathic (most common cause)
   2. Viral infection
      1. Infectious Mononucleosis
      2. Viral Hepatitis (non-A non-B non-C)
      3. Human Immunodeficiency Virus
   3. Medications
      1. Cancer Chemotherapy (common cause)
         1. Antileukemic medications
         2. Nitrogen mustard
      2. Chloramphenicol (1 per 60,000 courses)
      3. Phenylbutazone
      4. Phenytoin (Dilantin)
      5. Carbamazepine
      6. Sulfonamide
      7. Sulfonylurea
      8. Heavy metals (Gold, Arsenic, Mercury, bismuth)
      9. Quinacrine
      10. Chloroquine
      11. Antithyroid Drugs (e.g. Propylthiouracil)
      12. Carbonic anhydrase inhibitors (e.g. Acetazolamide)
      13. NSAIDs
      14. Antihistamines (Cimetidine, Chlorpheniramine)
      15. High dose Estrogen (e.g. Pregnancy)
   4. Immune Causes
      1. Eosinophilic fasciitis
      2. Hypoimmunoglobulinemia
   5. Toxins
      1. Radiation
      2. Insecticides (DDT, Lindane, Chlordane)
      3. Benzene (Kerosene, Carbon Tetrachloride, Chlorphenol)
   6. Miscellaneous
      1. Paroxysmal Nocturnal Hemoglobinuria
      2. Pregnancy
4. Causes: Inherited
   1. Dyskeratosis congenita
   2. Fanconi's Anemia
   3. Reticular dysgenesis
   4. Schwachman-Diamond Syndrome
   5. Familial Aplastic Anemia (Preleukemia)
5. Differential Diagnosis
   1. See Pancytopenia
6. Labs
   1. Complete Blood Count
      1. See Pancytopenia
   2. Peripheral Smear
      1. See Pancytopenia
   3. Bone Marrow Biopsy
      1. Hypoplastic marrow (fat infiltration)
7. Evaluation
   1. See Pancytopenia
8. References
   1. Bacigalupo in Rakel (2001) Conn's Therapy, p. 366-8
   2. Ravel (1995) Clinical Laboratory Medicine, p. 35-6
   3. Young in Goldman (2000) Cecil Medicine, p. 848-53