Pellagra
Encyclopedia
Pellagra is a vitamin
deficiency disease most commonly caused by a chronic lack of niacin
(vitamin B3) in the diet. It can be caused by decreased intake of niacin or tryptophan
, and possibly by excessive intake of leucine
. It may also result from alterations in protein metabolism in disorders such as carcinoid syndrome
. A deficiency of the amino acid
lysine
can lead to a deficiency of niacin as well.
, 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). This led to the disease being known as "Asturian leprosy", and it is recognized as the first modern pathological description of a syndrome. It was an endemic disease in northern Italy
, where it was named "pelle agra" (pelle = skin; agra = sour) by Francesco Frapoli of Milan
. 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, people also believed it was carried by insects. It was not until later that the lack of pellagra outbreaks in Mesoamerica
, where maize is a major food crop (and is processed), was noted and 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. 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 brewer's yeast prevented pellagra.
Goldberger performed an experiment using 11 volunteers from a prison, giving them clean clothes and keeping them in a house that was cleaned every day. Before the experiment, the prisoners were eating fruits and vegetables from the prison garden. Goldberger started feeding them only corn. About 2 weeks into the experiment the prisoners complained of headaches, confusion, and loss of appetite. In the third week, 7 of the 11 broke out in pellegra, and two prisoners begged for release. Goldberger cured them, feeding them fruits and vegetables again, and gave them their freedom. However, he failed to identify a specific element whose absence caused the pellagra. Goldberger continued his work but died of cancer without discovering the cause.
In 1937, Conrad Elvehjem
PhD of Madison, Wisconsin
showed 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 and 1950, it was found that the number of cases of women with pellagra was consistently double the number of cases of afflicted men. This is thought to be due to the inhibitory effect of estrogen
on the conversion of the amino acid tryptophan to niacin. 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. 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 quality protein foods to their children first. Women also would eat after everyone else had a chance to eat.
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".
Pellegra is no longer common in the United States.
from maize
(often called "corn"), notably rural South America
where maize is a staple food
. If maize is not nixtamalized
, it is a poor source of tryptophan as well as niacin. Nixtamalization of the corn corrects the niacin deficiency, and is a common practice in Native American cultures that grow corn. Following the corn cycle, the symptoms usually appear during spring, increase in the summer due to greater sun exposure, and return the following spring. Indeed, pellagra was once endemic
in the poorer states of the U.S. South, like Mississippi and Alabama, as well as among the inmates of jails and orphanages as studied by Dr. Joseph Goldberger
.
Pellagra is common in Africa
, Indonesia
, and China
. In affluent societies, a majority of patients with clinical pellagra are poor, homeless, alcohol-dependent, or psychiatric patients who refuse food. Pellagra was common among prisoners of Soviet labor camps, the Gulag
. It can be found in cases of chronic alcoholism
. In addition, pellagra is a micronutrient deficiency disease that frequently affects populations of refugees and other displaced people due to their unique, long-term residential circumstances and dependence on food aid. Refugees typically rely on limited sources of niacin provided to them, such as groundnuts; the instability in the nutritional content and distribution of food aid can be the cause of pellagra in displaced populations.
, dementia
and death.
A more comprehensive list of symptoms includes:
Frostig and Spies (acc. to Cleary and Cleary) described more specific psychological symptoms of pellagra as:
, an essential amino acid
found in soybeans, meat, poultry, fish, and eggs that the body converts into niacin. Third, it may be caused by excess leucine
, though the relationship is unclear.
Alterations in protein metabolism may also produce pellagra-like symptoms. An example of this is carcinoid syndrome
, a disease in which carcinoid
tumors produce excessive serotonin
. In normal patients, only one percent of dietary tryptophan is converted to serotonin; however, in patients with carcinoid syndrome this value may increase to 70 percent. The diversion of tryptophan to making serotonin in patients with metastatic tumors can result in tryptophan deficiency. Carcinoid syndrome thus may produce decreased protein synthesis, niacin deficiency, and clinical manifestations of pellagra.
, a chemical related to niacin. The frequency and amount of nicotinamide administered depends on the degree to which the condition has progressed.
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...
deficiency disease most commonly caused by a chronic lack of niacin
Niacin
"Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...
(vitamin B3) in the diet. It can be caused by decreased intake of niacin or tryptophan
Tryptophan
Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
, and possibly by excessive intake of leucine
Leucine
Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
. It may also result from alterations in protein metabolism in disorders such as carcinoid syndrome
Carcinoid syndrome
Carcinoid syndrome refers to the array of symptoms that occur secondary to carcinoid tumors. The syndrome includes flushing and diarrhea, and, less frequently, heart failure and bronchoconstriction...
. A deficiency of the amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
lysine
Lysine
Lysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
can lead to a deficiency of niacin as well.
History
The traditional food preparation method of corn (maize), nixtamalizationNixtamalization
Nixtamalization typically refers to a process for the preparation of maize , or other grain, in which the grain is soaked and cooked in an alkaline solution, usually limewater, and hulled. The term can also refer to the removal via an alkali process of the pericarp from other grains such as sorghum...
, by native New World
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
cultivators who had domesticated corn required treatment of the grain with lime
Calcium hydroxide
Calcium hydroxide, traditionally called slaked lime, is an inorganic compound with the chemical formula Ca2. It is a colourless crystal or white powder and is obtained when calcium oxide is mixed, or "slaked" with water. It has many names including hydrated lime, builders lime, slack lime, cal, or...
, an alkali
Alkali
In chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Some authors also define an alkali as a base that dissolves in water. A solution of a soluble base has a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base,...
. 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
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
in 1735 by Gaspar Casal, who published a first clinical description in his posthumous "Natural and Medical History of the Asturian Principality" (1762). This led to the disease being known as "Asturian leprosy", and it is recognized as the first modern pathological description of a syndrome. It was an endemic disease in northern Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, where it was named "pelle agra" (pelle = skin; agra = sour) by Francesco Frapoli of Milan
Milan
Milan is the second-largest city in Italy and the capital city of the region of Lombardy and of the province of Milan. The city proper has a population of about 1.3 million, while its urban area, roughly coinciding with its administrative province and the bordering Province of Monza and Brianza ,...
. Because pellagra outbreaks occurred in regions where maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
was a dominant food crop, the belief for centuries was that the maize either carried a toxic substance or was a carrier of disease, people also believed it was carried by insects. It was not until later that the lack of pellagra outbreaks in Mesoamerica
Mesoamerica
Mesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...
, where maize is a major food crop (and is processed), was noted and 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
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
or some unknown toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
in corn. The Spartanburg Pellagra Hospital in Spartanburg, South Carolina
Spartanburg, South Carolina
thgSpartanburg is the largest city in and the county seat of Spartanburg County, South Carolina, United States. It is the second-largest city of the three primary cities in the Upstate region of South Carolina, and is located northwest of Columbia, west of Charlotte, and about northeast of...
, 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
Joseph Goldberger
Joseph Goldberger, M.D. was a Hungarian Jewish physician and epidemiologist employed in the United States Public Health Service . He was an advocate for scientific and social recognition of the links between poverty and disease...
, assigned to study pellagra by the Surgeon General of the United States
Surgeon General of the United States
The Surgeon General of the United States is the operational head of the Public Health Service Commissioned Corps and thus the leading spokesperson on matters of public health in the federal government...
, 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 brewer's yeast prevented pellagra.
Goldberger performed an experiment using 11 volunteers from a prison, giving them clean clothes and keeping them in a house that was cleaned every day. Before the experiment, the prisoners were eating fruits and vegetables from the prison garden. Goldberger started feeding them only corn. About 2 weeks into the experiment the prisoners complained of headaches, confusion, and loss of appetite. In the third week, 7 of the 11 broke out in pellegra, and two prisoners begged for release. Goldberger cured them, feeding them fruits and vegetables again, and gave them their freedom. However, he failed to identify a specific element whose absence caused the pellagra. Goldberger continued his work but died of cancer without discovering the cause.
In 1937, Conrad Elvehjem
Conrad Elvehjem
Conrad A. Elvehjem, , was internationally known as a biochemist in nutrition. In 1937 he identified a molecule found in fresh meat and yeast as a new vitamin, nicotinic acid, now called niacin...
PhD of Madison, Wisconsin
Madison, Wisconsin
Madison is the capital of the U.S. state of Wisconsin and the county seat of Dane County. It is also home to the University of Wisconsin–Madison....
showed 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 and 1950, it was found that the number of cases of women with pellagra was consistently double the number of cases of afflicted men. This is thought to be due to the inhibitory effect of estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
on the conversion of the amino acid tryptophan to niacin. 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. 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 quality protein foods to their children first. Women also would eat after everyone else had a chance to eat.
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
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
. 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
Caries
Caries is a progressive destruction of any kind of bone structure, including the skull, ribs and other bones, or the teeth. Caries can be caused by osteomyelitis, which is a microorganism disease. A disease that involves caries is mastoiditis, an inflammation of the mastoid process, in which the...
were associated with "severe gingival retraction, sepsis
Sepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...
, exposure of cementum
Cementum
Cementum is a specialized calcified substance covering the root of a tooth. Cementum is excreted by cells called cementoblasts within the root of the tooth and is thickest at the root apex. These cementoblasts develop from undifferentiated mesenchymal cells in the connective tissue of the dental...
, and loosening of teeth".
Pellegra is no longer common in the United States.
Epidemiology
Pellagra can be common in people who obtain most of their food energyFood energy
Food energy is the amount of energy obtained from food that is available through cellular respiration.Food energy is expressed in food calories or kilojoules...
from maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
(often called "corn"), notably rural South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
where maize is a staple food
Staple food
A staple food is one that is eaten regularly and in such quantities that it constitutes a dominant portion of a diet, and that supplies a high proportion of energy and nutrient needs. Most people live on a diet based on one or more staples...
. If maize is not nixtamalized
Nixtamalization
Nixtamalization typically refers to a process for the preparation of maize , or other grain, in which the grain is soaked and cooked in an alkaline solution, usually limewater, and hulled. The term can also refer to the removal via an alkali process of the pericarp from other grains such as sorghum...
, it is a poor source of tryptophan as well as niacin. Nixtamalization of the corn corrects the niacin deficiency, and is a common practice in Native American cultures that grow corn. Following the corn cycle, the symptoms usually appear during spring, increase in the summer due to greater sun exposure, and return the following spring. Indeed, pellagra was once endemic
Endemic (epidemiology)
In epidemiology, an infection is said to be endemic in a population when that infection is maintained in the population without the need for external inputs. For example, chickenpox is endemic in the UK, but malaria is not...
in the poorer states of the U.S. South, like Mississippi and Alabama, as well as among the inmates of jails and orphanages as studied by Dr. Joseph Goldberger
Joseph Goldberger
Joseph Goldberger, M.D. was a Hungarian Jewish physician and epidemiologist employed in the United States Public Health Service . He was an advocate for scientific and social recognition of the links between poverty and disease...
.
Pellagra is common in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, and China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. In affluent societies, a majority of patients with clinical pellagra are poor, homeless, alcohol-dependent, or psychiatric patients who refuse food. Pellagra was common among prisoners of Soviet labor camps, the Gulag
Gulag
The Gulag was the government agency that administered the main Soviet forced labor camp systems. While the camps housed a wide range of convicts, from petty criminals to political prisoners, large numbers were convicted by simplified procedures, such as NKVD troikas and other instruments of...
. It can be found in cases of chronic alcoholism
Alcoholism
Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...
. In addition, pellagra is a micronutrient deficiency disease that frequently affects populations of refugees and other displaced people due to their unique, long-term residential circumstances and dependence on food aid. Refugees typically rely on limited sources of niacin provided to them, such as groundnuts; the instability in the nutritional content and distribution of food aid can be the cause of pellagra in displaced populations.
Symptoms
Pellagra is classically described by "the four D's": diarrhea, dermatitisDermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...
, dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
and death.
A more comprehensive list of symptoms includes:
- High sensitivity to sunlightPhotodermatitisPhotodermatitis, sometimes referred to as "sun poisoning" or photoallergy is a form of allergic contact dermatitis in which the allergen must be activated by light to sensitize the allergic response, and to cause a rash or other systemic effects on subsequent exposure...
- AggressionAggressionIn psychology, as well as other social and behavioral sciences, aggression refers to behavior between members of the same species that is intended to cause humiliation, pain, or harm. Ferguson and Beaver defined aggressive behavior as "Behavior which is intended to increase the social dominance of...
- DermatitisDermatitis-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...
, alopeciaAlopeciaAlopecia means loss of hair from the head or body. Alopecia can mean baldness, a term generally reserved for pattern alopecia or androgenic alopecia. Compulsive pulling of hair can also produce hair loss. Hairstyling routines such as tight ponytails or braids may induce Traction alopecia. Both...
, oedema - Smooth, beefy red glossitisGlossitisGlossitis is inflammation of the tongue. It causes the tongue to swell and change color. Finger-like projections on the surface of the tongue may be lost, causing the tongue to appear smooth....
- Red skin lesions
- InsomniaInsomniaInsomnia is most often defined by an individual's report of sleeping difficulties. While the term is sometimes used in sleep literature to describe a disorder demonstrated by polysomnographic evidence of disturbed sleep, insomnia is often defined as a positive response to either of two questions:...
- WeaknessWeaknessWeakness is a symptom represented, medically, by a number of different conditions, including: lack of muscle strength, malaise, dizziness, or fatigue. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a...
- Mental confusionMental confusionConfusion of a pathological degree usually refers to loss of orientation sometimes accompanied by disordered consciousness and often memory Confusion (from Latin confusĭo, -ōnis, noun of action from confundere "to pour together", also "to confuse") of a pathological degree usually refers to loss...
- AtaxiaAtaxiaAtaxia is a neurological sign and symptom that consists of gross lack of coordination of muscle movements. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum...
, paralysis of extremities, peripheral neuritis - DiarrheaDiarrheaDiarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
- Dilated cardiomyopathyDilated cardiomyopathyDilated cardiomyopathy or DCM is a condition in which the heart becomes weakened and enlarged and cannot pump blood efficiently. The decreased heart function can affect the lungs, liver, and other body systems....
- Eventually dementiaDementiaDementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
Frostig and Spies (acc. to Cleary and Cleary) described more specific psychological symptoms of pellagra as:
- Psycho-sensory disturbances (impressions as being painful, annoying bright lights, odours intolerance causing nausea and vomiting, dizziness after sudden movements)
- Psycho-motor disturbances (restlessness, tense and a desire to quarrel, increased preparedness for motor action)
- Emotional disturbances
Pathophysiology
Pellagra can develop according to several mechanisms, all of which ultimately revolve around niacin deficiency. The first is simple dietary lack of niacin. Second, it may result from deficiency of tryptophanTryptophan
Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
, an essential amino acid
Essential amino acid
An essential amino acid or indispensable amino acid is an amino acid that cannot be synthesized de novo by the organism , and therefore must be supplied in the diet.-Essentiality vs. conditional essentiality in humans:...
found in soybeans, meat, poultry, fish, and eggs that the body converts into niacin. Third, it may be caused by excess leucine
Leucine
Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
, though the relationship is unclear.
Alterations in protein metabolism may also produce pellagra-like symptoms. An example of this is carcinoid syndrome
Carcinoid syndrome
Carcinoid syndrome refers to the array of symptoms that occur secondary to carcinoid tumors. The syndrome includes flushing and diarrhea, and, less frequently, heart failure and bronchoconstriction...
, a disease in which carcinoid
Carcinoid
Carcinoid is a slow-growing type of neuroendocrine tumor, originating in the cells of the neuroendocrine system.In 2000, the World Health Organization redefined "carcinoid", but this new definition has not been accepted by all practitioners. This has led to some complexity in distinguishing...
tumors produce excessive serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
. In normal patients, only one percent of dietary tryptophan is converted to serotonin; however, in patients with carcinoid syndrome this value may increase to 70 percent. The diversion of tryptophan to making serotonin in patients with metastatic tumors can result in tryptophan deficiency. Carcinoid syndrome thus may produce decreased protein synthesis, niacin deficiency, and clinical manifestations of pellagra.
Prognosis
Untreated, the disease can kill within four or five years. Treatment is with nicotinamideNicotinamide
Nicotinamide, also known as niacinamide and nicotinic acid amide, is the amide of nicotinic acid . Nicotinamide is a water-soluble vitamin and is part of the vitamin B group...
, a chemical related to niacin. The frequency and amount of nicotinamide administered depends on the degree to which the condition has progressed.
Further reading
- Kraut, Alan. "Dr. Joseph Goldberger and the War on Pellagra, By Alan Kraut, Ph.D." Office of History, National Institutes of Health. Web. 03 Sept. 2010.