Question

A patient in the hospital for a wound infection is referred to you for consult. After 3 days of antibiotic therapy, the patient has gone from normal RBC results to a normocytic anemia with a slight macrocytosis (see image). The reticulocyte count is decreased. More significant is the development of a pronounced pancytopenia. A review of the charts reveals that this pancytopenia was not present upon admission. The patient has been on chloramphenicol therapy.

What is the most likely diagnosis?

Answer 1

The most likely diagnosis for the patient who developed pancytopenia after antibiotic therapy is chloramphenicol-induced bone marrow suppression, indicated by a decrease in all blood cell lines and a change in red blood cell morphology.

Step-by-step explanation:

The symptoms presented in the question, particularly the development of pronounced pancytopenia after antibiotic therapy, suggest the most likely diagnosis is chloramphenicol-induced bone marrow suppression. Chloramphenicol is known to cause dose-dependent or idiosyncratic bone marrow suppression, which can lead to a decrease in all three blood cell lines (red blood cells, white blood cells, and platelets), resulting in pancytopenia. The presence of normocytic anemia with slight macrocytosis and a decreased reticulocyte count after starting chloramphenicol also supports this diagnosis.