(ORDO NEWS) — Physicians from Trinidad and Tobago described excessive darkening of the skin in a black man. The patient has increased melanin synthesis due to B12 deficiency anemia, and because of this, the color of the feet and palms has changed.
Doctors diagnosed him with pernicious anemia, which is most often accompanied by fatigue, shortness of breath and dizziness. Darkening of the skin, especially in the absence of other symptoms, is rare with it. The case is described in The New England Journal of Medicine.
Anemia occurs due to a decrease in the hemoglobin content in red blood cells and is usually manifested by symptoms of tissue hypoxia: weakness, fatigue, shortness of breath and headache.
Also, depending on the cause of anemia, it may be accompanied by additional symptoms: jaundice during the destruction of red blood cells or a violation of the sensitivity of nerve fibers with vitamin B12 deficiency. In addition, in rare cases, very unusual symptoms occur.
So, with pernicious anemia (deficiency of vitamin B12), due to an increase in the synthesis of melanin in melanocytes, the skin and mucous membranes darken. The exact mechanism for the development of hyperpigmentation is unknown, and it occurs in only 10 percent of patients, so doctors often miss this symptom.
A case of pernicious anemia, which manifested itself only as hyperpigmentation of the skin, but helped to detect anemia in a timely manner, was described by doctors Sandeep Maharajh and Surujpal Teelucksingh from the University of the West Indies in Trinidad and Tobago.
They were approached by a 59-year-old black man with complaints of darkening of the skin on the feet and palms. The symptoms began to appear in him about a year ago, but at first he did not attach importance to them and connected them with his work – he worked as a tiler.
On examination, doctors found areas of hyperpigmentation on his tongue, as well as darkening of the feet and palms. Blood tests showed a decrease in hemoglobin and an increase in red blood cells, as well as a slight decrease in the number of platelets and white blood cells.
Hematologists suspected pernicious anemia associated with vitamin B12 deficiency in the patient. With this disease, red blood cells become abnormally large, since they need this vitamin for full development. The levels of vitamin B12 in the patient’s blood turned out to be five times lower than normal values (40 picograms per milliliter at a rate of 200-1100 picograms per milliliter).
When doctors began to look for the cause of anemia, they found that the man had antibodies to the internal factor of Castle, which is produced by the stomach. This compound binds vitamin B12 from food, and then the complex of the vitamin with intrinsic factor of Castle is absorbed in the ileum.
Doctors concluded that the man had autoimmune gastritis, and to correct anemia, he was prescribed intramuscular injection of vitamin B12, since the patient’s stomach could not absorb it naturally. Usually, when the vitamin deficiency is replenished, hyperpigmentation disappears, which happened in a man after four months of treatment.
A change in the color of the skin and mucous membranes often indicates a malfunction in the body. For example, an American woman’s tongue turned blue because of antibodies to an enzyme involved in the synthesis of adrenal hormones. The color change turned out to be reversible, but the woman will have to take hormone replacement therapy for life.
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