Pellagra sufferer with skin lesions
Pellagra is a deficiency disease caused by lack of the B complex vitamin niacin (B3, or nicotinic acid), either from a dietary lack of niacin and the essential amino acid tryptophan, or from an inability to properly absorb or metabolize niacin. Because tryptophan can be converted into niacin, foods with tryptophan but without niacin, such as milk, prevent pellagra. However, if dietary tryptophan is diverted into protein production, niacin deficiency may still result.
Pellagra is an endemic disease in Africa, Mexico, Indonesia, and China. In affluent societies, a majority of patients with clinical pellagra are poor, homeless, alcohol dependent, or psychiatric patients who refuse food (Jagielska et al. 2007).
As a nutritional disorder, pellagra is a preventable disease, requiring a diet adequate in niacin-rich foods or appropriate supplementation (Carson-DeWitt 2004). However, in many areas of the world, pellagra is a condition of poverty, as such niacin-rich foods are unavailable to some people.
A vitamin deficiency disease, pellegra generally is brought about by dietary lack of niacin (B3) and protein, especially proteins containing the essential amino acid tryptophan, which can be converted into niacin (Pitche 2005).
However, there are two types of pellagra. Primary pellagra involves a diet extremely deficient in niacin-rich foods or niacin being present in a form that cannot be absorbed. For example, this type of pellagra is common in areas where maize is the dietary staple, because while it contains niacin, it cannot be absorbed unless treated with alkali (as is done in the preparing tortillas) (Carson-DeWitt 2004). Secondary pellagra occurs when there are adequate quantities of niacin in the diet, but other conditions or diseases interfere with its absorption or processing, such as in cases of prolonged diarrhea, cirrhosis of the liver, alcoholism, and with use of the anti-tuberculosis drug isoniazid (Carson-DeWitt 2004). Also Hartnup disease results in disordered absorption of amino acids from the intestine and kidney (Carson-DeWitt 2004).
Niacin is part of the B vitamins or the vitamin B complex, a group of water-soluble vitamins. Niacin is found in foods such as yeast, liver, meat, fish, legumes, and whole-grain cereals (Carson-DeWitt 2004).
Tryptophan is an amino acid found in most proteins. It is classified as an "essential amino acid" since it cannot be synthesized by the human body from other compounds through chemical reactions and thus has to be taken in with the diet. Tryptophan is found in soybeans, meat, poultry, fish, and eggs. If one's diet contains these foods, one's need for niacin from other sources will be reduced (Haas 1992). Conversion of tryptophan to niacin is insufficient by itself to fully meet the demands for this vitamin, but it can help forestall pellagra. Lack of tryptophan, however, such as dependence on food of low tryptophan content such as maize (corn), can contribute to this niacin-deficiency disease.
Pellagra can be common in people who obtain most of their food energy from corn, since untreated corn is a poor source of niacin. Corn is also a poor source of tryptophan. This disease can be common among people who live in rural South America where corn is a staple.
It is one of several diseases of malnutrition common in Africa. It was also endemic in the poorer states of the U.S. South, like Mississippi and Alabama, as well as among the inmates of jails and orphanages, where it was studied by Joseph Goldberger who conducted experiments in the penal colony in Rankin. Alkali treatment of the corn corrects the niacin deficiency, and this was a common practice in Native American cultures that grew corn. Pellagra was common among prisoners of Soviet labor camps, the infamous Gulag. It can be found in cases of chronic alcoholism.
The relationship between leucine and pellagra is unclear (Bapurao and Krishnaswamy 1978).
Pellagra causes a number of symptoms affecting the skin, mucous membranes, central nervous system, and gastrointestinal tract. Common symptoms include:
The main results of pellagra can easily be remembered as "the four D's": diarrhea, dermatitis, dementia, and death (Hegyi et al. 2004).
Early patients may have only a light skin rash, but over time the skin becomes progressively thickened and pigmented, and may slough off in places. The mouth and tongue, and sometimes the vagina, may become progressively swollen, red, and thickened. There may be abdominal pain, nausea, and vomiting, and bloody diarrhea (Carson-DeWitt 2004).
There are a number of mental changes associated with pellagra. This includes insomnia, fatigue, and apathy, progressing to memory loss, confusion, depression and hallucination (Carson-DeWitt 2004). There also may be impressions as being painful, annoying bright lights, odors intolerance, dizziness after sudden movements, restlessness, tenseness and a desire to quarrel (Cleary and Cleary 1989). There may be the development of involuntary grasping and sucking movements and variations in level of consciousness (Carson-DeWitt 2004).
Diagnosis is based on patient diet history as well as patients recollection of symptoms. There are no chemical tests, but the patient can be placed on a diet sufficient in niacin and seeing the response of the patient (Carson-DeWitt 2004).
Treatment of pellagra involves supplementing the diet, often with a form of niacin called niacinamide, since pure niacin has unpleasant side effects. It can be given orally or by injection (Carson-DeWitt 2004). The frequency and amount of niacinamide administered depends on the degree to which the condition has progressed.
Untreated, the disease will continue progressing and can kill within four or five years. Death often is due to complications from infections, blood loss, sever encephalophatic syndrome, or massive malnutrition from continuous diarrhea (Carson-DeWitt 2004).
The traditional food preparation method of corn, nixtamalization, by native New World cultivators who had domesticated corn required treatment of the grain with lime, an alkali. It has now been shown that the lime treatment makes niacin nutritionally available and reduces the chance of developing pellagra. When corn cultivation was adopted worldwide, this preparation method was not accepted because the benefit was not understood. The original cultivators, often heavily dependent on corn, did not suffer from pellagra. Pellagra became common only when corn became a staple that was eaten without the traditional treatment.
Pellagra was first described in Spain in 1735 by Gaspar Casal, who published a first clinical description in his posthumous "Natural and Medical History of the Asturian Principality" (1762). It was an endemic disease in northern Italy, where it was named "pelle agra" (pelle means "skin," and agra means "rough") by Francesco Frapoli of Milan (MedicineNet 2003).
Because pellagra outbreaks occurred in regions where maize was a dominant food crop, the belief for centuries was that the maize either carried a toxic substance or was a carrier of disease. It was not until later that the lack of pellagra outbreaks in Mesoamerica, where maize is a major food crop (and is processed), that the idea was considered that the causes of pellagra may be due to factors other than toxins.
In the early 1900s, pellagra reached epidemic proportions in the American South. There were 1,306 reported pellagra deaths in South Carolina during the first ten months of 1915; 100,000 Southerners were affected in 1916. At this time, the scientific community held that pellagra was probably caused by a germ or some unknown toxin in corn (Bollet 1992). The Spartanburg Pellagra Hospital in Spartanburg, South Carolina, was the nation's first facility dedicated to discovering the cause of pellagra. It was established in 1914 with a special congressional appropriation to the U.S. Public Health Service (PHS) and set up primarily for research. In 1915, Joseph Goldberger, assigned to study pellagra by the Surgeon General of the United States, showed that pellagra was linked to diet by inducing the disease in prisoners, using the Spartanburg Pellagra Hospital as his clinic. By 1926, Goldberger established that a balanced diet or a small amount of baker's yeast prevented pellagra. Skepticism nonetheless persisted in the medical community until 1937, when Conrad Elvehjem showed that the vitamin niacin cured pellagra (manifested as black tongue) in dogs. Later studies by Tom Spies, Marion Blankenhorn, and Clark Cooper established that niacin also cured pellagra in humans, for which Time Magazine dubbed them its 1938 Men of the Year in comprehensive science.
In the research conducted between 1900-1950, it was found that the number of cases of women with pellagra was consistently double the number of cases of afflicted men (Miller 1978). This is thought to be due to the inhibitory effect of estrogen on the conversion of the amino acid tryptophan to niacin (Brenton 2000). It is also thought to be due to the differential and unequal access to quality foods within the household. Some researchers of the time gave a few explanations regarding the difference (Carpenter 1981). As primary wage earners, men were given consideration and preference at the dinner table. They also had pocket money to buy food outside the household. Women gave protein quality foods to their children first. Women also would eat after everyone else had a chance to eat. Women also upheld the triad of maize, molasses, and fat back pork, which combine to contribute to cause pellagra.
Gillman and Gillman related skeletal tissue and pellagra in their research in South African Blacks. They provide some of the best evidence for skeletal manifestations of pellagra and the reaction of bone in malnutrition. They claimed radiological studies of adult pellagrins demonstrated marked osteoporosis. A negative mineral balance in pellagrins was noted which indicated active mobilization and excretion of endogenous mineral substances, and undoubtedly impacted the turnover of bone. Extensive dental caries were present in over half of pellagra patients. In most cases caries were associated with "severe gingival retraction, sepsis, exposure of cementum, and loosening of teeth" (Gillman and Gillman 1951).
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