Pellagra is a vitamin deficiency caused by a deficiency of vitamin PP and tryptophan amino acids. The main symptoms are redness, peeling of the skin on the face and neck, hair loss, ulceration of the tongue, diarrhea, numbness and tingling in the extremities, paralysis, insomnia, weakness, distraction, decreased intellectual functions (dementia). The diagnosis is established on the basis of the history, clinical picture, biochemical examination of blood and urine. The treatment is based on nicotinic acid replacement therapy, a nutritious diet high in foods rich in B vitamins.
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 doctor Frapolli studied her clinical manifestations in more detail and introduced the term “pellagra” into the scientific literature – a name popular among the general population and reflecting the main external symptom of the disease – dermatitis . In the 19th century, pellagra was widespread in the southern countries of Europe and in the south of the USA – in regions with a uniform diet and a predominance of starchy vegetables. Currently, epidemiological indicators are highest in poorly developed African and South American countries. Around the world, the disease is more often diagnosed in patients suffering from chronic alcoholism .
Causes of Pellagra
The pathology is based on vitamin PP deficiency. Its synonymous names are vitamin B3, nicotinic acid, niacin. It enters the body with food, and 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 diet. Vitamin deficiency develops during fasting, following strict diets, a uniform 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.
- Digestive apparatus diseases. 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 with gastritis, hepatitis , ulcerative colitis and Crohn’s disease .
- Alcoholism. Alcohol inactivates vitamins in the stomach and intestines, interferes with their absorption, destroys liver cells, which produce proteins necessary for the absorption of vitamins. In addition, patients with alcoholism often eat incompletely, starve, which increases the risk of vitamin deficiency.
- Increased 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 overwork and stress, especially against the background of malnutrition.
- syndrome. Carcinoid tumors produce excess serotonin using tryptophan. Up to 70% of this amino acid is consumed by the tumor and metastases . Tryptophan deficiency occurs, and as a result, vitamin PP deficiency.
Niacin is a participant in the reactions of protein metabolism, DNA synthesis, RNA, cholesterol and fatty acids. It is a coenzyme of NAD-dependent dehydrogenases and NADP-dependent enzymes, providing 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 sources of energy 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, and a decrease in the number of red blood cells.
Energy deficit affects the work of the nervous system most of all: polyneuritis develops , cognitive functions decrease, up to dementia . The level of sugar and cholesterol (LDL) in the bloodstream rises, the production of sex hormones, thyroxine, cortisol, insulin decreases. These changes provoke diseases of the digestive tract, anemia, hormonal imbalance, hyperglycemia and vascular atherosclerosis .
Symptoms of Pellagra
Three classic manifestations of pathology are dermatitis, digestive upset, and neuromuscular dysfunction. 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 occur. Edematous reddenings of a bright burgundy color appear, blisters with turbid contents, which gradually become red-brown. After opening the bladder, an ulcer or erosion is formed. Rashes are often located on the legs, arms, neck and face, intensified by exposure to sunlight. After them, areas of hyperpigmentation are preserved , peeling and keratinization of the upper layers begin.
The mucous membranes of the nasal passages, mouth, eyes and genitals become inflamed, swollen. On the surface of the eyelids erythema in the form of crescents are formed. Peeling is often observed around the eyes, on the back of the nose. The manifestation of “ Casal ‘s collar ” is characteristic – the erythema site in the form of a strip framing the neck and descending in the center of the chest. Skin lesions are localized on the wrists, back of the palms, phalanges. The ankle joints are “encircled” by an erythema strip; papules surrounded by areas of hemorrhage are poured on the hips and legs.
In addition to diarrhea, dyspeptic disorders in pellagra are represented by burning and salty smack in the mouth, swelling of the lips and tongue, cracks in the corners of the mouth. The tongue becomes bright red, shiny, with ulcerations, teeth marks. Signs of stomatitis are found in the oral cavity : small bleeding sores, white spots on the mucous membrane, swelling and redness. Patients suffer from bloating, diarrhea, alternating with constipation, heartburn, nausea, and vomiting. Neurological and neuropsychiatric disorders include polyneuritis, local loss of sensation, paresthesia, fatigue and exhaustion, apathy, irritability, insomnia and depression . Violation of mental functions gradually increases from mild forgetfulness and distraction to a gross decline in memory and intelligence (dementia).
In rare cases, pellagra is acute. With this option, there are no classic skin symptoms, the disease begins with an attack similar to a stroke . Vomiting and diarrhea appear abruptly, and seizures develop when touched . There is muscle hypertonicity : “stone” stiffness of the masticatory apparatus, stiffness of the arms and legs. Body temperature rises, swelling increases, fluid accumulates in the abdominal cavity, consciousness is darkened, patients hallucinate. Often the attack is fatal.
Without adequate treatment, pellagra has a wave-like course with periodic deterioration of the patient’s condition. Exacerbating in the warm season, for 5-6 years, it leads to severe dementia with loss of speech, simple motor and everyday skills. Patients are in a state of psychosis, in which psychomotor agitation , delirium and hallucinations predominate . Encephalopathy , muscle hypertonicity develops , sucking and grasping reflexes resume (development regression). The risk of stroke, myocardial infarction , scurvy increases . If untreated, pellagra ends in death 5–8 years after the onset of symptoms.
Examination of patients with suspected pellagra is carried out 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, therefore, the diagnosis is confirmed after a positive reaction to replacement therapy with nicotinic acid preparations. The standard set of diagnostic procedures includes:
- Clinical and anamnestic survey. The survey often reveals that the patient is malnourished, purposefully or forcedly starving, suffering from chronic alcoholism or diseases of the digestive organs. Complaints of skin rashes, pain, itching and burning in the feet and hands, diarrhea are characteristic. The decrease in cognitive functions is usually not noticed by patients, but manifests itself 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. In many patients, blisters are found in open areas of the skin, papules on the legs, 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. In urine, a low content of metabolites of nicotinic acid and tryptophan is determined.
Medical care is provided to patients in a hospital. During treatment, complete physical and mental peace is provided. The main goals of therapy are to fill the deficiency of vitamins 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 reduced. Additionally, the intake of vitamins B2, B1, B6 and B12 is prescribed
- Diet therapy. For all patients, a high-calorie diet is prepared with the inclusion of products having a high content of vitamin PP, C, tryptophan and proteins. The menu contains meat, dairy products, eggs, mushrooms, fruits, vegetables, nuts and whole grains.
- Symptomatic treatment. To eliminate dermatitis, corticosteroid ointments and creams are used, with digestive disorders, achlorhydria – hydrochloric acid, pancreatic enzymes. Diarrhea is treated with antibiotics, sulfonamides. Antidepressants and tranquilizers are shown to patients with depression, anxiety .
Forecast and Prevention
The outcome of pellagra is largely determined by the timeliness of treatment. With this disease, irreversible complications quickly develop, so the earlier the vitamin deficiency is filled, the more favorable the prognosis. The main preventive measure is a varied and complete diet. The body should receive a sufficient amount of protein and vitamins daily. 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 with the aim of early detection of hypovitaminosis.