Pellagra is a vitamin deficiency caused by a deficiency of vitamin PP and the amino acid tryptophan. The main symptoms are redness, peeling of the skin on the face and neck, hair loss, ulceration on the tongue, diarrhea, a feeling of numbness and tingling in the extremities, paralysis, insomnia, weakness, absent–mindedness, decreased intellectual functions (dementia). The diagnosis is established on the basis of anamnesis, clinical picture, biochemical examination of blood and urine. Treatment is based on nicotinic acid replacement therapy, a full diet with a high content of foods rich in B vitamins.
E52 Nicotinic acid deficiency [pellagra]
The word “pellagra” comes from the Italian language and translates as “rough skin”. The disease was first described in 1735 in Spain. In 1771, the Italian physician Frapolli studied its clinical manifestations in more detail and introduced the term “pellagra” into the scientific literature – a name popular among the common population and reflecting the main external symptom of the disease – dermatitis. In the XIX century, pellagra was widespread in the southern countries of Europe and in the south of the USA – in regions with a monotonous diet and a predominance of starchy vegetables. Currently, epidemiological indicators are highest in poorly developed African and South American countries. Worldwide, the disease is more often diagnosed in patients suffering from chronic alcoholism.
The pathology is based on vitamin PP deficiency. Its synonymous names are vitamin B3, nicotinic acid, niacin. It enters the body with food, can be synthesized from tryptophan – an essential amino acid. Deficiency of vitamins B1, B2 and B6 plays a role in the development of the disease. Many researchers and doctors consider pellagra as a result of multivitamin deficiency. Its causes may be:
- Poor unbalanced nutrition. Vitamin deficiency develops with fasting, strict diets, a monotonous diet in which there are no sources of tryptophan and nicotinic acid. A large number of them are found in mushrooms, nuts, poultry, meat, fish and eggs.
- Diseases of the digestive system. In the digestive tract, vitamins are absorbed into the blood, and their transport and metabolism are provided by enzymes and proteins produced by the liver. Violation of these processes occurs in gastritis, hepatitis, ulcerative colitis and Crohn’s disease.
- Alcoholism. Alcohol inactivates vitamins in the stomach and intestines, prevents their absorption, destroys liver cells that produce proteins necessary for the absorption of vitamins. In addition, patients with alcoholism often eat poorly, starve, which increases the risk of vitamin deficiency.
- An increase in the need for vitamins. The consumption of vitamins by the body increases during pregnancy, lactation and acute infectious diseases. Also, the probability of pellagra increases with chronic fatigue and stress, especially against the background of insufficient nutrition.
- Carcinoid syndrome. Carcinoid tumors produce an excess of serotonin using tryptophan. Up to 70% of this amino acid is consumed by the tumor and metastases. There is a deficiency of tryptophan, and, as a result, a lack of vitamin PP.
Niacin participates in the reactions of protein metabolism, synthesis of DNA, RNA, cholesterol and fatty acids. It is a coenzyme of NAD-dependent dehydrogenases and NADP-dependent enzymes, providing the processes of tissue respiration, carbohydrate and amino acid metabolism, and lipid synthesis. With vitamin deficiency, the rate of redox reactions decreases and the formation of ATP molecules, the main energy sources in cells, is disrupted. As a result, the process of tissue renewal slows down, which is primarily manifested by damage to the skin and mucous membranes, a decrease in the number of red blood cells.
Energy deficiency has the strongest effect on the work of the nervous system: polyneuritis develops, cognitive functions decrease up to dementia. The level of sugar and cholesterol (LDL) in the bloodstream increases, the production of sex hormones, thyroxine, cortisol, and insulin decreases. These changes provoke diseases of the digestive tract, anemia, hormonal imbalance, hyperglycemia and atherosclerosis of blood vessels.
Three classic manifestations of pathology are dermatitis, digestive disorders and disorders of neuromuscular functions. The disease usually has a chronic form, develops within a few months. It debuts with persistent diarrhea and nonspecific symptoms, such as fatigue, weakness, drowsiness. After 2-3 months, local lesions of the mucous membranes and skin appear. There are edematous redness of a bright burgundy color, blisters with cloudy contents, which gradually becomes red-brown. After opening the bladder, an ulcer or erosion forms. Rashes are often located on the legs, arms, neck and face, and are intensified by exposure to sunlight. After them, areas of hyperpigmentation are preserved, peeling and keratinization of the upper layers begins.
The mucous membranes of the nasal passages, oral cavity, eyes and genitals become inflamed, swell. On the surface of the eyelids, erythema forms in the form of crescents. Peeling is often observed around the eyes, on the back of the nose. The manifestation of the “Casal collar” is characteristic – a section of erythema in the form of a strip framing the neck and descending along the center of the chest. Skin lesions are localized on the wrists, the back of the palms, and the phalanges. The ankle joints are “girdled” with a band of erythema, papules are poured out on the hips and shins, surrounded by areas of hemorrhage.
In addition to diarrhea, dyspeptic disorders in pellagra are represented by burning and salty taste in the mouth, swelling of the lips and tongue, cracks in the corners of the mouth. The tongue becomes bright red, shiny, with ulceration, traces of teeth. Signs of stomatitis are found in the oral cavity: small bleeding ulcers, white spots on the mucous membrane, swelling and redness. Patients suffer from bloating, diarrhea, alternating constipation, heartburn, nausea, vomiting. Neurological and neuropsychiatric disorders include polyneuritis, local loss of sensitivity, paresthesia, fatigue and exhaustion, apathy, irritability, insomnia and depression. The violation of mental functions gradually increases from mild forgetfulness and absent-mindedness to a gross decrease in memory and intelligence (dementia).
In rare cases, pellagra is acute. In this case, there are no classic skin symptoms, the disease begins with an attack similar to a stroke. Vomiting and diarrhea appear sharply, convulsions develop when touched. There is muscle hypertonicity: “stone” stiffness of the chewing apparatus, rigidity of the arms and legs. Body temperature rises, swelling increases, fluid accumulates in the abdominal cavity, consciousness darkens, patients hallucinate. Often the attack ends in a fatal outcome.
Without adequate treatment, pellagra has a wave-like nature of the course with periodic deterioration of the patient’s condition. Aggravating in the warm season, for 5-6 years it leads to severe dementia with loss of speech, simple motor and household skills. Patients are in a state of psychosis, in which psychomotor agitation, delirium and hallucinations prevail. Encephalopathy develops, muscle hypertonicity, sucking and grasping reflexes resume (regression of development). The risk of stroke, myocardial infarction, scurvy increases. In the absence of treatment, pellagra ends in death 5-8 years after the onset of symptoms.
Examination of patients with suspected pellagra is conducted by a dermatologist, less often a gastroenterologist, neurologist, psychiatrist. Differential diagnosis involves the exclusion of diseases such as erysipelas, solar dermatitis and Hartnup syndrome. Highly specific research methods have not been developed, so the diagnosis is confirmed after a positive reaction to nicotinic acid replacement therapy. The standard set of diagnostic procedures includes:
- Clinical and anamnestic survey. During the survey, it often turns out that the patient eats poorly, purposefully or involuntarily starves, suffers from chronic alcoholism or diseases of the digestive organs. Typical complaints of skin rashes, pain, itching and burning in the feet and hands, diarrhea. A decrease in cognitive functions is usually not noticed by patients, but is manifested in conversation.
- Inspection. A characteristic feature is dermatitis on the chest, neck, face, arms and legs. There may be specific signs of the disease: erythema crescents on the eyelids, a “collar” on the neck, peeling on the nose and near the eyes. Many patients have blisters on open areas of the skin, papules on the shins, redness on the wrist and ankle joints.
- Biochemical analysis. Blood and urine are examined. Pellagra is characterized by a decrease in the level of tryptophan in the blood, a decrease in the concentration of NADP and NAD in red blood cells. A low content of metabolites of nicotinic acid and tryptophan is determined in the urine.
Medical care is provided to patients in a hospital setting. Complete physical and mental rest is provided for the duration of treatment. The main goals of therapy are to make up for vitamin deficiency and eliminate the symptoms of the disease. Depending on the severity of the patient’s condition, therapeutic measures last from 1 to 6 months, include:
- Vitamin therapy. Nicotinic acid or nicotinamide preparations are used. At the beginning of the course, the vitamin is administered intramuscularly or intravenously, by the end of the course – orally. The dose is determined by the severity of the disease, always gradually decreases. Additionally, vitamins B2, B1, B6 and B12 are prescribed
- Diet therapy. For all patients, a high-calorie diet is compiled with the inclusion of products with a high content of vitamin PP, C, tryptophan and proteins. The menu includes meat, dairy products, eggs, mushrooms, fruits, vegetables, nuts and whole grains.
- Symptomatic treatment. To eliminate dermatitis, corticosteroid ointments and creams are used, for digestive disorders, achlorhydria – hydrochloric acid, pancreatic enzymes. Treatment of diarrhea is carried out with antibiotics, sulfonamides. Antidepressants and tranquilizers are indicated for patients with depression and anxiety.
Prognosis and prevention
The outcome of pellagra is largely determined by the timeliness of treatment. Irreversible complications develop rapidly with this disease, therefore, the earlier the vitamin deficiency is replenished, the more favorable the prognosis. The main preventive measure is a varied and complete diet. The body should receive a sufficient amount of proteins and vitamins every day. Pregnant women, women during lactation, people experiencing physical or mental stress need additional intake of multivitamin complexes. Patients with pathologies of the digestive system require periodic monitoring of the level of vitamins and amino acids in the body in order to detect hypovitaminosis early.