From the Research
The Bluegrass disease of Kentucky, also known as methemoglobinemia, is inherited as an autosomal recessive trait. This condition is caused by a rare recessive gene that results in reduced ability to convert methemoglobin to hemoglobin, leading to a bluish appearance of the skin. The affected individuals had inherited two copies of the recessive gene (one from each parent), which is characteristic of autosomal recessive inheritance patterns. Some key points to consider in the treatment of methemoglobinemia include:
- Methylene blue is a common treatment for methemoglobinemia, but it can be problematic in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, as it can cause hemolysis 1.
- Leucomethylene blue may be a safer alternative for treating methemoglobinemia in patients with G6PD deficiency, as it is an antioxidant and direct reducing agent for Fe3+ 2.
- The diagnosis of methemoglobinemia should be relatively straightforward with an occupational history, and clinical observations such as the victim being less unwell than expected from the severity of 'cyanosis' and the 'cyanosis' being unresponsive to oxygen therapy 3.
- Pulse oximetry is unreliable in the presence of methemoglobinemia, and arterial blood gas analysis is mandatory in severe poisoning 3.
- High-flow oxygen should be given to maximize oxygen carriage by remaining ferrous hem, and methylene blue can be administered at a dose of 1-2 mg/kg intravenously, depending on the severity of the features 3, 4.