Dapsone-Induced Methemoglobinemia: A Case Report.

Here, we present the case of a 64-year-old male with a rare cause of cyanosis due to dapsone-induced methemoglobinemia who was treated successfully with methylene blue and high-dose Vitamin C. Our case emphasizes the importance of history taking, knowledge, and high index of suspicion of drug-induced methemoglobinemia, especially in the presence of saturation gap. This condition can be fatal if left untreated.