Dapsone-Induced Methemoglobinemia: A Case Report

Area of Science:

• Internal Medicine
• Clinical Pharmacology
• Toxicology

Background:

• Methemoglobinemia is a condition where hemoglobin is oxidized, reducing oxygen transport.
• Dapsone is a medication known to induce methemoglobinemia as a rare side effect.
• Cyanosis, a bluish discoloration of the skin, can be a presenting symptom.

Observation:

• A 64-year-old male presented with cyanosis.
• The cyanosis was identified as a rare case of dapsone-induced methemoglobinemia.
• A saturation gap was noted, suggesting impaired oxygen saturation.

Findings:

• The patient's methemoglobinemia was successfully treated with methylene blue and high-dose Vitamin C.
• This case underscores the importance of a thorough medical history and a high index of suspicion for drug-induced methemoglobinemia.
• Prompt diagnosis and treatment are crucial as untreated methemoglobinemia can be fatal.

Implications:

• Clinicians should consider drug-induced methemoglobinemia in patients presenting with cyanosis, particularly when a saturation gap is present.
• Methylene blue and Vitamin C are effective treatment options for dapsone-induced methemoglobinemia.
• Raising awareness about this rare but serious adverse drug reaction can improve patient outcomes.