Methemoglobinemia (blue people): symptoms, causes and treatment
Our skin is an organ that is often undervalued and recognized , which protects our organism against a large number of harmful elements such as bacteria, fungi and solar radiation.
This important part of our body, however, in addition to protecting us on occasion also warns us of the presence of alterations in other areas of our body and that may have serious implications for health. This is what happens for example in jaundice, in which the skin acquires yellowish tones.
Another of the disorders in which abnormal skin staining appears is methemoglobinemia, an alteration of blood origin in which the skin becomes bluish in color and depending on its type can bring fatal consequences.
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Methemoglobinemia: what it is, and symptoms
We call methemoglobinemia a strange blood disorder characterized by the presence of an excessive level of a subtype of hemoglobin called methemoglobin. This particular type of hemoglobin does not have the ability to carry oxygen , and at the same time interferes with the hemoglobin that is able to do it in such a way that the latter can not release it in the different organs and tissues normally. This causes the oxygenation of the organism to be reduced.
This disorder has as one of its most evident symptoms and easily visible cyanosis, or blue coloration of the skin (although the tones can vary, it is usually an intense bluish color). This probably derives from the aforementioned decrease in the oxygenation of the organism . And not only the skin: the blood also changes color losing its characteristic red to become brownish.
However, skin coloring is not the only problem that can arise: if the excess of methemoglobin is too large, the lack of oxygen in the rest of the body can lead to organ problems and even death. It is not uncommon for respiratory problems to appear, and this is usually one of the main causes of hospitalization.
In addition to the above, depending on the type of methemoglobinemia we can find headaches, fatigue, seizures and respiratory problems with deadly potential (in case it is due to acquired causes) or the emergence of intellectual disability and maturational delays in the case of congenital type 2 methemoglobinemia, which will be discussed later.
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Typologies according to their causes
The causes of the appearance of this disorder can be multiple, and can appear both congenitally and acquired.
Acquired methemoglobinemia is the most frequent and usually appears derived from the consumption or exposure to oxidizing drugs or chemical substances such as bismuth nitrate, as well as elements used to treat some ailments such as nitroglycerin or some antibiotics.
Concerning congenital methemoglobinemia, it is usually due to genetic transmission or the appearance of certain mutations. We can find two basic types.
The first one is generated by the genetic inheritance of both parents, both parents being carriers (although most of them have not expressed the disorder). a mutation of certain genes that cause a problem in the enzyme citrochrome b5 reductase . This enzyme does not act correctly in the body, which generates an oxidation of hemoglobin.
Within this type of congenital methemoglobinemia we can find two major types: congenital methemoglobinemia type 1 is that the aforementioned enzyme does not appear in the red blood cells of the organism and type 1 in which the enzyme does not appear directly in any part of the organism.
The other option within the congenital metahemoglobinemias is the so-called hemoglobin M disease, in which this alteration appears because the hemoglobin is structurally altered base. In these cases we are facing an autosomal dominant disorder in which it is enough for one of the parents to carry the gene and transmit it to generate the alteration (something similar to what happens with Huntington's Korea).
Treatment of this condition
Although it may seem hard to believe, methemoglobinemia is a medical condition that has curative treatment in some cases.
In most cases the prognosis is positive and the patient can recover completely. Mainly the treatment is to generate a reduction in methemoglobin levels and an increase in hemoglobin with oxygen transport capacity, injecting methylene blue (except in those patients who are at risk of suffering G6PD deficiency, in which it can be dangerous) or other substances with similar effect.
If it does not work, hyperbaric chamber treatment can be used. The consumption of vitamin C can also be useful, although its effect is less.
In the case of acquired methemoglobinemia, the withdrawal of the substance that caused the alteration is also required. Mild cases may not require more measurement than this, but in people with respiratory or cardiac problems the treatment described above is required.
The changes with these treatments can be spectacular , changing the coloring of the skin at high speed.
However, in the case of congenital type 2 methemoglobinemia, the disease is much more complicated and its prognosis is much more serious, with the infant's death being common during the first years.
Bibliographic references:
- Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013: chap 41. Available at: //medlineplus.gov/ency/article/000562.htm
- Goldfrank, R. L, (2006). Goldfrank's Toxicologic Emergencies. 8th. Edition New York USES.
- Roman, L. (2011). 18-year-old woman with methemoglobinemia after using topical anesthetic cream. Journal of the Clinical Laboratory, 4 (1) .: 45-49.
