Jul 06, 2018
Pellagrais a systemic pathology of the human body, manifested in the appearance of symptoms of the defeat of the digestive and nervous system, as well as the apparent changes in the skin that are caused by the pronounced insufficiency of vitamins of all subgroups B and nicotinic acid.
There are a number of pathological conditions that are background conditions for the development of signs of pellagra, but the development of this pathology is most often formed with a nutritional deficiency of B vitamins, nicotinic acid, and organic pathologies of severe abdominal organs.
Currently, the frequency of the classic variant of pellagra has decreased significantly, and the pellagra in children is a historical fact.
In the development of signs of pellagra, as the main manifestation of the insufficient content of nicotinic acid and the main groups of vitamin B, the greatest pathogenetic significance is the defeat of the digestive tract, due to the fact that most of the diseases of the gastroenterological profile is accompanied by vitamin deficiency. Most often, the pathology of the small intestine becomes the cause of the patient's symptoms of pellagra, as in this section of the digestive tract is absorption of vitamins B, as well as nicotinic acid, like most other groups of vitamins and vitamin-like substances. Background diseases that trigger the development of pellagra are: resection of the small intestine, chronic enteritis and the formation of gastrointestinal fistula.
In addition, the severe form of pellagra accompanies the course of acute infectious diseases localized in the intestines, the most common forms of which are intestinal tuberculosis and dysentery. With prolonged abuse of alcohol, conditions are also created to suppress the absorption capacity of the small intestine, which inevitably leads to the development of vitamin deficiencies in certain categories of vitamins.
As with any form of vitamin deficiency, the pellagra can develop not because of a lack of vitamins B, but at excessive consumption, which occurs even in the normal course of pregnancy and the period of breastfeeding, and against the background of increased physical activity, combined with starvation.
If we consider the pathogenetic mechanisms of the development of pellagra, the main role in the formation of lesions of internal organs, structures of the nervous system and skin is impaired metabolism of vital elements, especially carbohydrates, occurring at the cellular level. However, the starting mechanism in the pathogenesis of the development of typical clinical manifestations of pellagra is the insufficient content of the amino acid tryptophan in the human body.
With the progression of the disease, the patient develops irreversible processes in the skin and nervous system structures that are degenerative. In a situation where the pellagra develops in an absolutely healthy person against a disturbed diet, the primary variant of the disease should be understood. If the development of signs of pellagra is provoked by pathological changes in internal organs of a chronic nature, then a diagnosis of the secondary variant of pellagra is established.
Due to the fact that the pellagra is accompanied by severe metabolic disturbances in the patient's body, its pathomorphological manifestations are quite wide. Changes in degenerative nature are noted in tissues of various origins( skin, endocrine organs, skeletal muscles, nervous system structures and organs of the digestive tract).
With the development of a detailed clinical picture, patients suffering from pellagra note the appearance of a wide range of symptoms. Due to the large list of patient complaints, with primary contact with the patient it is difficult to establish a correct diagnosis, however, detailed anamnestic data suggest the presence of a given pathology in humans. As a rule, the patient's primary treatment for medical care is formed in the presence of various signs of a dyspeptic symptom complex( complete absence of appetite, and sometimes even aversion to food intake, a feeling of dryness and burning in the mouth, distortion of taste preferences), and with the progression of the disease patientcomplains of a violation of the functioning of the intestine in the form of alternating periods of relaxation of stool and constipation.
With the increase of toxic syndrome, the patient notes progressive weakness, inability to perform usual physical activity, dizziness and lack of interest in life. Most often, patients with pellagra occupy a passive position "lying on their backs."
In the diagnosis of pellagra, the primary objective examination of the patient is of great importance, which is accompanied by the detection of a whole spectrum of pathognomonic symptoms allowing the diagnosis to be correctly established. When visual inspection of the oral cavity, the patient is marked by a pronounced hyperemia not only of the tongue, but also of the mucous cheeks, gums with the presence of small ulcers, which in some situations may have signs of hemorrhagic impregnation. Similar changes in the mucous membranes are observed in the projection of the esophagus and stomach, but for their visualization the patient must perform esophagogastroscopy.
With the prolonged course of pellagra, many small bleeding erosions appear in the thick and thin sections of the intestine, which can be accompanied by the appearance of a blood admixture in the feces found in the analysis of feces for "latent blood".
Anemia syndrome with pellagra, as a rule, is quite pronounced and is accompanied by all clinical manifestations characterizing this pathological condition.
The primary criterion for damage to the structures of the nervous system in pellagra is the appearance of signs of polyneuritis of different localization, which are primarily accompanied by a violation of all sensitivities without a pronounced pain component. With the progression of pellagra degenerative processes affect the structure of the brain, in connection with which, the patient develops cerebral and focal neurological symptoms( headache, impaired coordination, vomiting, impaired vision, memory, hearing, etc.).
When the endocrine structures are affected, the patient develops polyglandular insufficiency in the form of a tendency to arterial hypotension, adynamia, progressive muscle weakness, polyuria and osteoporotic lesion of bone tissue of a widespread nature.
Violation of protein and vitamin metabolism is more reflected in laboratory indicators and is accompanied by the development of pronounced hypoproteinemia due to a decrease in the albumin fraction.
It should be noted that pellagra can occur in both acute and prolonged clinical variant, each of which has its own characteristic features. For the development of the acute form of pellagra, the trigger mechanism must be expressed alimentary deficiency of exogenous nature. The debut of the disease in this situation is a sharp increase and loosening of the stool, the frequency of urging for an act of defecation can reach 20 times a day. A few days later, the patient develops severe psychoneurological disorders( delirium), greatly complicating the patient's condition. With the continuing vitamin deficiency, the patient displays typical skin signs of pellagra.
The prolonged course of pellagra is difficult for early diagnosis, as for a long time this category of patients is observed in neurologists about sluggish polyneuritis. Subsequently, symptoms of a psycho-neurological nature that also do not differ in specificity are added. And only after the appearance of skin symptoms develops a classical version of the flow of pellagra.
The primary lesion of the skin with pellagra is their increased dryness and discoloration towards the gray shade. Most of the above manifestations are localized along the lateral surfaces of the abdomen and back, as well as on the extensor surface of the extremities. Against the background of these changes, reddening of the skin of the upper body and distal parts of the limbs, resulting from exposure to ultraviolet irradiation, is quite contrasting. A characteristic feature of erythema in this case is its clear contours, which are the boundary between the affected and unchanged skin areas. If the patient has an acute clinical variant of pellagra, the above changes in the skin are supplemented by the phenomena of exudative inflammation, manifested as the appearance of blisters with hemorrhagic contents. The healing process of the inflammatory skin elements is characterized by a long period and is accompanied by the development of massive cicatricial deformities.
Changes in the skin on the face with pellagra are accompanied by characteristic pathognomonic changes in the form of the formation of "pellagrotic glasses"( brown hyperpigmentation of the eyelids with peeling) and "the collar of Kasal"( erythema stripe on the neck and chest).
With pellagra, the appearance of secondary skin elements in the form of follicular papules, localized in the projection of the shin and thigh, with a clear even hemorrhagic bezel.
Complications of pellagra consist in the transition of the disease into an acute form, often resulting in a fatal outcome. In this situation, the diagnosis of the disease is extremely difficult, since the patient is marked by a lightening increase in the phenomena of neurological nature, sometimes not differing from other intracerebral pathologies( increased tendon reflexes, convulsive readiness, severe degree of impaired consciousness, rigidity of the limbs, visual hallucinations, vomiting and triasm of the masticatory muscles).In this case, a reliable diagnosis is possible only when examining the sectional material.
Patients with diagnosed pellagra must be treated in a hospital in compliance with the conditions of complete physical and psycho-emotional rest. The only pathogenetically justified direction of drug treatment is substitution therapy with application of Amide Nicotinic Acid in parenteral or oral form. A saturated daily dose of the drug should be 0.3 g for at least six weeks, after which it is necessary to switch to a maintenance dose of 50 mg, mainly by oral administration.
Parenteral( intramuscular) administration of nicotinic acid amide is limited to a mass of adverse reactions in the form of a painful sensation of heat, reddening of the upper half of the trunk and itching of the skin, although this way of administering the drug is much more effective.
Given the pathogenetic mechanisms of the development of pellagra, it is advisable to supplement the substitution therapy with B vitamins in the parenteral form( Thiamine in a daily dose of 20 mg, Riboflavin 10 mg and Pyridoxine 50 mg).Indication for the appointment of vitamin B12 is the presence of signs of macrocytosis, glossitis and hyperchromia. The presence of severe anemic syndrome should be cured by fractional blood transfusions of 100 ml once every five days.
During the period of elimination of acute manifestations of pellagra and against the background of the applied substitution therapy, it is necessary to conduct a conversation with the patient on the topic of correction of eating behavior. The main criterion for a proper diet in this situation is saturation of the daily menu with products with a high concentration of B vitamins, ascorbic and nicotinic acid, and also protein foods.