pernicious

pernicious /per·ni·cious/ (per-nish´us) tending toward a fatal issue.

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per·ni·cious (pr-nshs)

adj.

Tending to cause death or serious injury; deadly.

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pernicious

[pərnish′əs]

Etymology: L, perniciosus, destructive

potentially injurious, destructive, or fatal unless treated, such as pernicious anemia.

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pernicious [per-nish´us]

tending to a fatal outcome.

pernicious anemia a type of megaloblastic anemia seen most often in older adults, caused by lack of intrinsic factor, which normally is produced by the stomach mucosa. The deficiency results in inadequate and abnormal formation of erythrocytes, leukocytes, and platelets, with failure to absorb vitamin B₁₂. Some patients show only mild symptoms and are not particularly aware of the illness; in others it becomes very serious and if untreated can lead to permanent neurologic impairment and even death. It may be caused by deficient vitamin B₁₂ intake, impaired absorption due to intrinsic factor deficiency or intrinsic intestinal disease or increased requirements and impaired utilization.

Symptoms. A pale, colorless, or lemon-yellow complexion is typical. jaundice also occurs, with soreness and reddening of the tongue, difficulty in swallowing, and digestive disturbances such as diarrhea. Other symptoms may include fatigability, heart palpitation, and dyspnea. Changes in the nerves and spinal cord may produce numbness and tingling in the fingers and toes, and the gait may become unsteady; involvement of the nerves can be avoided if the condition is detected and treated in the early stages. Laboratory tests reveal abnormalities in the erythrocytes in the blood and in the bone marrow. Gastric analysis shows an absence of hydrochloric acid and perhaps even an absence of gastric juice.

Treatment. Pernicious anemia is successfully treated by regular injections of vitamin B₁₂, given several times a week at first and monthly after the condition has been brought under control. This treatment must be lifelong to prevent relapse. The injections do not cure the disease but arrest it by providing the body directly with the necessary vitamin that it fails to absorb from the digestive tract. Special diets, liver extract, and other medications taken by mouth usually are not required since the basic defect is not dietary deficiency but improper use of food ingested. The etiology of pernicious anemia is unknown although there appears to be an autoimmune component, as anti–intrinsic factor antibodies are often found. For patient care, see also anemia.

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pernicious

tending to a fatal issue.

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pernicious anemia

a form of anemia in humans caused by a genetically determined lack of the intrinsic factor, which normally is produced by the stomach mucosa. The deficiency results in inadequate and abnormal formation of erythrocytes, and failure to absorb vitamin B₁₂. Not reported in animals.

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pernicious

adjective Bad/not real good