Methemoglobinemia differential diagnosis
![](/images/1/16/Home_logo1.png)
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aksiniya Stevasarova, M.D.
Overview
Methemoglobinemia must be differentiated from other diseases that cause hypoxia and cyanosis, such as heart failure, pulmonary embolism, polycythemia, anemia, etc.
Differentiating Methemoglobinemia from other Diseases
- There are several conditions that can present similar to methemoglobinemia. Note that the hypoxia in methemogobinemia will be unresponsive to oxygen treatment, in comparison to cardiac and pulmonary cause. Worth mentioning is that high doses of antidotal treatment for methemogobinemia (Methylene blue) can also cause cyanotic discoloration of the skin, but this does not mean the the treatment is not working.
- Methemoglobinemia can present with similar signs and symptoms of other conditions causing hypoxia (as listed below). Note that the hypoxia in methemogobinemia will be unresponsive to oxygen treatment, in comparison to cardiac and pulmonary causes of hypoxia.
• Rasbirucase (Rx Tumor Lysis Syndrome) [2]
• Asthma
- High doses of antidote treatment for methemogobinemia - (Methylene blue) can also cause cyanotic discoloration of the skin as a side effect, but this should not lead you into thinking that the treatment is inefficient. [3]
- Depending on the levels of MetHb in the blood we can observe different clinical presentation as follows[3] [4]
- MetHb levels of 15% lead to skin and blood color (chocolate-brown) changes .
- MetHb levels above 15% lead to hypoxia.
- MetHb levels above 70% lead to death.
References
- ↑ Soliman DS, Yassin M (2018). "Congenital methemoglobinemia misdiagnosed as polycythemia vera: Case report and review of literature". Hematol Rep. 10 (1): 7221. doi:10.4081/hr.2018.7221. PMC 5907642. PMID 29721250.
- ↑ Khan M, Paul S, Farooq S, Oo TH, Ramshesh P, Jain N (2017). "Rasburicase-Induced Methemoglobinemia in a Patient with Glucose-6- Phosphate Dehydrogenase Deficiency". Curr Drug Saf. 12 (1): 13–18. doi:10.2174/1574886312666170111151246. PMID 28078984.
- ↑ 3.0 3.1 do Nascimento TS, Pereira RO, de Mello HL, Costa J (2008). "Methemoglobinemia: from diagnosis to treatment". Rev Bras Anestesiol. 58 (6): 651–64. PMID 19082413.
- ↑ Bradberry SM (2003). "Occupational methaemoglobinaemia. Mechanisms of production, features, diagnosis and management including the use of methylene blue". Toxicol Rev. 22 (1): 13–27. PMID 14579544.