Review Question - QID 211083

This patient with new-onset fatigue, pallor, and prolonged bleeding most likely has aplastic anemia caused by chloramphenicol treatment. Aplastic anemia is associated with hypocellular bone marrow with fatty infiltration.

Aplastic anemia presents with pancytopenia caused by a decrease in the number of hematopoietic stem cells. Therefore, patients will present with symptoms of anemia such as fatigue and conjunctival pallor, symptoms of platelet deficiency such as mucosal bleeding, and symptoms of leukopenia such as recurrent infections. Aplastic anemia can be caused by radiation, drugs, viruses, and autoimmune diseases. Drugs that are particularly associated with aplastic anemia include the antibiotic chloramphenicol, antiepileptics such as carbamazepine, and chemotherapy drugs such as alkylating agents. Diagnosis can be confirmed by bone marrow biopsy showing hypocellular bone marrow with fatty infiltration.

Incorrect Answers:
Answer 1: Dense lines in the metaphysis of long bones would be associated with lead poisoning anemia; however, this process would not explain the prolonged bleeding seen in this patient. Furthermore, this patient does not have abdominal pain or neuropathy which would be characteristic of lead poisoning.

Answer 2: Hypersegmented neutrophils would be associated with anemia due to folate or vitamin B12 deficiency; however, these processes would not explain the increased bleeding seen in this patient.

Answer 4: Low circulating levels of erythropoietin would be associated with anemia of renal failure; however, this process would not explain the prolonged nosebleeds seen in this patient.

Answer 5: Schistocytes on peripheral blood smear would be characteristic of microangiopathic anemias; however, these processes would also present with neurologic changes as well as fever.

Bullet Summary:
Aplastic anemia presents with symptoms of anemia, thrombocytopenia, and leukopenia due to a decrease in production of all three lines.