Iron deficiency anemia in children
Introduction
Introduction to iron deficiency anemia in children Irondeficiencyanaemia (IDA) is the most common type of anemia in infants and young children. The incidence of children under 2 years old in China is 10% to 48.3%. The underlying cause of the disease is a small cell hypochromic anemia caused by a deficiency of iron in the body, resulting in a decrease in hemoglobin synthesis. In addition to anemia, it can also reduce the biological activity of many iron-containing enzymes due to iron deficiency. Affecting the metabolism of cells, causing a series of non-blood system manifestations such as digestive tract dysfunction, circulatory dysfunction, immune dysfunction, neurological symptoms and skin mucosal lesions, which are harmful to children's health, so it is an important prevention and treatment in China. One of the pediatric diseases. The disease has a good prognosis. After treatment with iron, it can be cured. If it can improve the diet, remove the cause, rarely relapse. For very severe patients, due to serious infection and indigestion, the rescue is not timely and may result in death. For patients with late treatment, although anemia is completely restored, physical development and mental development will be affected. basic knowledge Sickness ratio: 0.50% Susceptible people: more common in young children Mode of infection: non-infectious Complications: malabsorption syndrome, malnutrition in children
Cause
Causes of iron deficiency anemia in children
Body iron content at birth (25%):
Normal neonatal blood volume is about 85ml/kg, hemoglobin is about 190g/L, and more than 75% of total iron in the neonatal period is in hemoglobin, about 15%-20% is stored in the reticuloendothelial system, synthesizing myoglobin. The amount is very small, the iron in the enzyme is only a few milligrams, so the iron content in the newborn is mainly determined by the blood volume and the concentration of hemoglobin. The blood volume is proportional to the body weight, and a 3.3kg newborn is given up with a 1.5kg premature birth. In comparison with infants, the total amount of iron in the body differs by 120 mg. In normal newborns, the iron content in the body is about 70mg/dl. The amount of iron in premature infants and low birth weight infants is directly proportional to their body weight. The iron released by physiological hemolysis after birth is stored in reticuloendothelial cells, plus enough iron to store. The application of weight gain after birth is doubled, so the lower the birth weight, the less the total amount of iron in the body, the greater the possibility of anemia. In addition, the fetal transfusion of the placenta to the mother, or the transfusion of one of the twins to another A fetus, as well as rupture of the placenta in the placenta and ligation of the biliary band (delayed by umbilical cord ligation, which can give newborns 75 ml of blood or 40 mg of iron) may affect the iron content of the newborn.
Growing too fast (20%):
Children grow rapidly and blood volume increases rapidly. Normal infants gain 1 time when they grow to 5 months, and premature infants increase faster. If they are 1 year old, they can increase 6 times. If the newborn blood protein is 19g/dl to 4.5-5 It drops to about 11g/dl at the time of the month. At this time, only the stored iron can be maintained. There is no need to add iron to the food, but the premature baby is different, and the demand is much higher than that of the normal baby.
Normal infants gain 1 time and maintain hemoglobin at 11g/dl. The iron stored in the body is sufficient. Therefore, if there is obvious iron deficiency anemia before weight gain, it is not caused by iron deficiency in the diet. Must look for other reasons.
Dietary iron deficiency (15%):
Infants are mainly dairy foods. The iron content of such foods is extremely low. The content of iron in breast milk is related to the mother's diet. Generally, the iron content is 1.5mg/L, the cattle is 0.5~1.0mg/L, and the goat milk is less. The absorption rate of iron in the class is about 2% to 10%, and the absorption rate of iron in human milk is higher than that in milk (the iron absorption rate in human milk can be increased to 50% when iron is deficient), and if the baby has enough within 6 months after birth The amount of breast milk should be fed to maintain the hemoglobin and stored iron in the normal range. Therefore, when breastfeeding is not possible, the formula of iron should be fed and the complementary food should be added in time. Otherwise, the iron stored after the weight gain is doubled. And after the anemia can occur, breast-fed infants can also develop anemia after 6 months without adding complementary foods. According to the etiology of 39 cases of small cell anemia in Beijing Children's Hospital, 65% are artificial feeding, and some breast-feeding people are Supplementary foods were not added in time. The larger children had poor eating habits, refused to eat, partial eclipse or poor nutrition and caused anemia.
Long-term small blood loss (20%):
The iron stored in normal people is 30% of the total iron volume of the human body. For example, acute blood loss does not exceed 1/3 of the total blood volume. Although it can be quickly recovered without additional iron supplementation, it will not cause anemia, long-term chronic blood loss. 4ml per blood loss, about equal to 1.6mg of iron loss, although the amount of blood loss is not much per day, but the iron consumption has more than doubled than normal, can cause anemia, infants within 1 year of age due to rapid growth, stored iron are used In order to supplement the expansion of blood volume, a small amount of chronic blood loss can also lead to anemia. In recent years, it has been found that chronic intestinal blood loss can occur in children fed a large amount (>1L) of uncooked fresh milk. Anti-heat-resistant protein in fresh milk can be found in the blood of such children. Some people think that intestinal blood loss is related to the amount of fresh boiled milk that is not boiled. If the baby is 2 to 12 months old, take it daily. The total amount of fresh milk does not exceed 1L, (preferably not more than 750ml) or the application of evaporated milk, blood loss can be reduced. Common chronic blood loss can also be caused by gastrointestinal malformations, phlegm, polyps, ulcer disease, esophageal varices, hookworm disease, epistaxis, thrombocytopenic purpura, pulmonary hemosiderosis and teenage menstruation.
Other reasons (5%):
Long-term diarrhea and vomiting, enteritis, fatty phlegm, etc., can affect the absorption of nutrients. In acute and chronic infections, the appetite of children is reduced, the gastrointestinal tract is not well absorbed, and iron deficiency anemia can also be caused.
Prevention
Prevention of iron deficiency anemia in children
First, do a good job in infant feeding.
Iron is better absorbed in breast milk, and it is best to use breastfeeding. If breastfeeding is not available, use reinforced iron formula.
1. Add a diet that strengthens iron.
Full-term infants start from 4 to 6 months (not later than 6 months). Premature infants and low-weight infants start from 3 months and strengthen the iron content in the diet. The easiest way is to add ferrous sulfate to the milk or to the complementary food, such as iron-containing cereals or alternating use of ferrous sulfate drops. The dosage of pure iron in full-term children of ferrous sulfate drops should not exceed 1 mg/kg/day (2.5% FeSO40.2 ml/kg/day), and the premature infants should not exceed 2 mg/kg/d. The maximum total daily dose is 15 mg. However, it should not be used for more than one month in the home to avoid iron poisoning. In addition, artificially fed children should not exceed 750 ml of milk without iron after 6 months.
2, children and adults
It is best to add 13 to 16 mg of iron per kg of flour, and at the same time pay attention to increasing the animal diet.
Second, do a good job in health checkups, regular anemia screening, so early detection and early treatment.
Complication
Complications of iron deficiency anemia in children Complications, malabsorption syndrome, malnutrition in children
Complications of iron deficiency anemia in children are extramedullary hematopoiesis, ecstasy, atrophic gastritis or malabsorption syndrome, memory loss, heart enlargement and cardiac insufficiency; due to low immune function, often concurrent infection, childhood developmental disorders, metabolic disorders Loss of appetite, slower weight gain, atrophy of the tongue nipple, decreased gastric acid secretion, and intestinal mucosal dysfunction.
Symptom
Symptoms of iron deficiency anemia in children Common symptoms Red blood cell low iron deficiency anemia fatigue loss of appetite loss of appetite, lack of energy, irritability, hepatosplenomegaly, acute anemia
The incidence is mostly from 6 months to 3 years old, most of them are slow onset, and most of them are not paid attention to by parents. Most of the sick children have been moderately anemia at the time of treatment. The mild symptoms of symptoms depend on the degree of anemia and anemia. speed.
1. General performance: At first, there are often irritability or lack of energy, lack of activity, loss of appetite, pale skin and mucous membranes, lips, oral mucosa, nail bed and palm are most obvious. Preschool and school-age children can be self-reported at this time. Powerless.
2, the performance of hematopoietic organs: due to extramedullary hematopoietic reaction, liver, spleen and lymph nodes are often mildly enlarged, the younger the age, the more anemia, the longer the course of the disease, the more obvious the hepatosplenomegaly, but the swelling rarely crosses the moderate .
3. In addition to changes in the hematopoietic system, iron deficiency has an effect on metabolism. From a cytological point of view, it can lead to a lack of cytochrome system; catalase, glutathione peroxidase, succinate dehydrogenase , monoamine oxidase, aconitase and -phosphoglyceryl dehydrogenase and other enzymes have reduced activity; and affect DNA synthesis, due to metabolic disorders, loss of appetite, weight loss, tongue nipple atrophy, gastric acid secretion reduction and small intestine Mucosal dysfunction, heterosexuality is more common in adults, less common in children.
4. Changes in neuropsychiatry have gradually attracted attention. It has been found that when anemia is not serious, irritability and uneasiness are caused, and the surrounding environment is not interested. The intelligence test finds that the sick child is not focused, the understanding is reduced, the response is slow, and the infant is young. Breathing bolding spells can occur. School-age children behave abnormally in class, such as chaos, non-stop small movements, etc. These phenomena are not very good in the relationship between iron and iron. The concentration of norepinephrine in the urine of patients with iron anemia is increased, and it returns to normal after iron administration, suggesting that neuropsychiatric changes may be related to norepinephrine degradation and metabolism. The increase of norepinephrine in urine may be caused by the lack of monoamine oxidase. An iron-dependent enzyme that plays a role in the neurochemical reaction of the central nervous system. It has been determined that the activity of monoamine oxidase in platelets of patients with iron deficiency anemia is reduced, and it returns to normal soon after taking iron, in order to further affirm iron deficiency. In relation to neuropsychiatric symptoms, it seems that more research work on animal experiments should be done in the future.
5, iron deficiency anemia children are more susceptible to infection, such patients with E rosettes, active E rosette formation rate are reduced, PHA and other skin test reactions are significantly lower than normal, indicating that T lymphocytes function is weak, there are Reported that the peripheral blood T lymphocyte subsets CD3CD4 lymphocytes decreased the OKT4/OKT8 ratio decreased, there are also reports that the patient's NBT test is lower than normal, may be caused by the reduction of iron-containing myeloperoxidase, so the granulocyte killing ability is reduced, After treatment with iron, the bactericidal function of granulocytes returned to normal.
6, when hemoglobin is reduced to below 70g / L, there may be heart enlargement and murmur, which is the general manifestation of anemia rather than the special signs of iron deficiency anemia, due to the slow onset of iron deficiency anemia, the body is strong, when When hemoglobin drops to 40g/L for a while, there is no manifestation of cardiac insufficiency, but after a respiratory infection, the heart burden is aggravated and heart failure can be induced.
Examine
Examination of iron deficiency anemia in children
1, biochemical testing
Before the onset of anemia, a series of biochemical changes occur. When iron is deficient, the body first uses stored iron to maintain the need for iron metabolism. The content of ferritin and hemosiderin in the liver and bone marrow is reduced. Ferritin is reduced, the normal value of serum ferritin is 35 ng/ml. If it is reduced to below 10 ng/ml, biochemical or clinical iron deficiency can occur. After that, serum iron drops below 50 g/dl, even as low as 30 g/dl. In the following, when the serum iron binding capacity is increased to 350 g/dl or more, the transferrin saturation is reduced to 15% or less, and the transferrin saturation is less than 15%, the hemoglobin synthesis is reduced, and the red blood cell free protoporphyrin accumulation can be as high as 60g/dl whole blood, the increase of the ratio of erythrocyte free protoporphyrin to hemoglobin (FEP/Hgb) in infants and young children is more meaningful for the diagnosis of iron deficiency anemia than the decrease of transferrin protein. The ratio of >3g/g is considered as Abnormal, if between 5.5 ~ 17.5g / g, after the exclusion of lead poisoning, can be diagnosed as iron deficiency anemia, serum copper increased up to 146g / dl, if the iron deficiency continues to progress, there is a change in blood.
2, blood elephant
Both red blood cells and hemoglobin are decreased, hemoglobin is decreased, hematocrit is correspondingly reduced, and the mean red blood cell volume (MCV) is less than 80 fl, which can be as low as 51 fl; the mean hemoglobin (MCH) of red blood cells is less than 26 pg, and the lowest is 11.1 pg; The hemoglobin concentration (MCHC) is lower than 0.30, which can be as low as 0.20. The average red blood cell is as low as 70pg according to the measurement of a few cases. The red blood cells in the smear become smaller, and most of the diameters are less than 6m, sometimes varying in size, mostly in small cases. The Price-Jones curve is shifted to the left, and the basement is widened, the red blood cells are lightly stained, and the middle translucent area is enlarged. In severe cases, the red blood cells may be ring-shaped, the percentage of network red blood cells is normal, but the absolute value is lower than normal, and the red blood cell fragility is lowered. Nucleated red blood cells are rarely seen in the surrounding blood.
The white blood cell morphology is normal and the count is normal, but the number of white blood cells may be reduced in severe cases, and the relative increase of lymphocytes occurs. The majority of platelets are within the normal range, and the severe cases may be slightly reduced, but the degree of bleeding is rarely reached.
3, bone marrow
The bone marrow is proliferating, the bone marrow cell count is slightly increased, and the number of megakaryocytes is normal. According to the statistics of Beijing Children's Hospital, the bone marrow cell count is between 150,000 and 400,000/mm3, with an average of 300,000/mm3, and megakaryocytes are more than 25 Between ~125/mm3, on average about 70/mm3.
The ratio of granulocytes to nucleated red blood cells in the classification of bone marrow showed increased nucleated red blood cells, indicating that erythrocyte proliferation was strong, granulocyte cell morphology was unchanged, neutrophils were slightly higher in categorical counts, and erythrocyte lineage counts, medium and young erythrocytes. And the increase of young red blood cells, especially the increase of young and middle red blood cells, early, young, young and late red blood cells with less cytoplasm, hemoglobin content is very small, showing that the maturity of the mature lag behind the nucleus, cytoplasm The edges are not neat, and stained with potassium ferrocyanide, the iron granulocytes are reduced or even disappeared, and blue ferritin and hemosiderin are not seen in the smears.
4, other inspections
If there is chronic intestinal blood loss, fecal occult blood is positive, the condition is serious, and the course of disease is long. The X-ray film of the skull can be seen as a radiation-like streak change of hemoglobin disease. B-ultrasound can be found in hepatosplenomegaly and the heart is enlarged. X-ray examination is performed. When the lung infection is complicated, the inflammatory shadow is seen and the heart can be enlarged.
Diagnosis
Diagnosis and diagnosis of iron deficiency anemia in children
diagnosis
The diagnosis of IDA should be combined with the feeding history, birth weight, age of onset, clinical signs and symptoms, and blood characteristics. Generally, a preliminary diagnosis can be made, and then the necessary laboratory tests can be combined to make a definite diagnosis, but attention should be paid to the diagnosis. Iron deficiency anemia is only the first step. The complete diagnosis should include the diagnosis of the cause. Therefore, in order to determine the cause or primary disease of anemia, further examination is needed: such as fecal occult blood, urine routine, liver and kidney function, gastrointestinal X-ray, Gastroscopy and corresponding biochemical, immunological examinations, etc., do not identify the cause, anemia can not only cure, and sometimes hide some serious diseases, sometimes the primary disease is more harmful to patients than anemia.
Clinically, iron deficiency and iron deficiency anemia are divided into three stages: iron deficiency, iron deficiency erythropoiesis and iron deficiency anemia. The diagnostic criteria are as follows:
1. Iron deficiency or potential iron deficiency
At this time, only the consumption of iron stored in the body can be diagnosed according to (1) plus any one of (2) or (3).
1, there are clear causes of iron deficiency and clinical manifestations.
2, serum ferritin <14g / L.
3. Bone marrow iron staining showed that iron granule cells were <10% or disappeared, and extracellular iron was absent.
Second, iron deficiency erythropoiesis
It refers to the red blood cell intake of iron is less than normal, but the reduction of intracellular hemoglobin is not obvious, in line with the diagnostic criteria of iron deficiency, and any of the following can be diagnosed.
1. Transferrin saturation <15%.
2. Erythrocyte free protoporphyrin >0.9 mol/L.
Third, iron deficiency anemia
The hemoglobin in red blood cells is significantly reduced, showing small cell hypochromic anemia. The diagnosis is based on:
1. Comply with the diagnosis of iron deficiency and iron deficiency erythropoiesis.
2, small cell hypochromic anemia.
3, iron treatment is effective.
Iron therapeutic test: In patients with iron deficiency anemia, reticulocyte counts increase rapidly after several days of continuous oral administration of iron, generally on the 5th to 10th day after taking iron, reticulocytes are increased to 4%~ 10%, and other anemias do not have this kind of reaction. This kind of diagnostic test is simple and easy, but the results are slower. If the patient has iron absorption disorder, the result cannot be judged. The latter case can be treated with iron injection. Make a diagnosis and note that the patient should not have taken iron before the test.
Differential diagnosis
1. Thalassemia
Family history, regional characteristics are obvious, special face, liver and spleen swelling, blood smears visible target cells and nucleated red blood cells, hemoglobin electrophoresis A2 and F increased, or hemoglobin H or Bart s, etc., serum iron increased , iron cells in the bone marrow increased.
2, pulmonary hemosiderosis
It is characterized by paroxysmal paleness, weakness, cough, blood in the sputum, hemosiderin cells can be found in the sputum and gastric juice, reticulocytes are increased, and ray-like shadows are visible in the X-ray chest radiograph.
3, iron granulocyte anemia
The extracellular iron in the bone marrow smear was significantly increased. The iron particles around the nucleus of the middle and late erythrocytes were arranged in a ring shape, and the serum iron was increased. The treatment with iron was ineffective. Some patients could achieve better curative effect with vitamin B6.
4, chronic infectious anemia
Most of them are small cell orthochromatic anemia, occasionally low chroma, serum iron and iron binding are reduced, iron cells in the bone marrow increase, iron therapy does not respond.
5, lead poisoning
The basophilic spot color is observed in the red blood cells, the lead content in the serum is increased, the protoporphyrin in the red blood cells and urine is significantly increased, and the FEP/Hgb can be as high as 17.5 g/g or more.
