Pancytopenia in an infant associated with sulfamethoxazole-trimethoprim therapy

Area of Science:

• Pediatric Hematology
• Pharmacology
• Toxicology

Background:

• Pancytopenia is a serious condition characterized by a deficiency in all three major blood cell types.
• Sulfamethoxazole-trimethoprim is a commonly prescribed antibiotic combination.
• Aplastic anemia typically presents with a hypocellular bone marrow.

Observation:

• A seven-month-old infant developed pancytopenia.
• The condition was linked to sulfamethoxazole-trimethoprim treatment.
• Initial bone marrow examination revealed prominent plasma cells and histiocytes.

Findings:

• The infant's bone marrow morphology was distinct from the usual presentation of aplastic anemia.
• This case suggests a potential adverse drug reaction to sulfamethoxazole-trimethoprim.
• The prominent plasma cells and histiocytes represent an unusual bone marrow finding in drug-induced pancytopenia.

Implications:

• This case highlights the importance of considering drug-induced pancytopenia in infants presenting with low blood counts.
• Clinicians should be aware of the atypical bone marrow findings associated with sulfamethoxazole-trimethoprim.
• Further investigation may be warranted to understand the mechanism of this adverse reaction.