Congenital lactose intolerance

Introduction Congenital lactose intolerance: This is a disease that is different from congenital lactase deficiency and belongs to autosomal dominant inheritance. After starting feeding, there was fulminant diarrhea, acidy stool with watery vesicles, and diarrhea. Can cause vomiting, dehydration, renal tubular acidosis, disaccharide, amino aciduria, cataract, liver and brain damage, such as diagnosis can cause death. The diarrhea disappeared after stopping the feeding, and there was no lactoseuria or amino aciduria. When the lactose that has not been decomposed and absorbed enters the colon, the bacteria present in the intestine are fermented into small molecules of organic acids such as acetic acid, propionic acid, butyric acid, etc., and some gases such as methane, H2, CO2, etc. are produced, and most of these products can be Lactose reabsorbed by the colon, but not absorbed or still not decomposed can cause bowel, abdominal distension, abdominal pain, exhaust, discomfort, diarrhea and other symptoms, and some people may have hernia, nausea and so on.

Cause

Five reasons for congenital lactose intolerance:

1. Congenital lactase deficiency: refers to the low or lack of lactase activity at birth, which is caused by the recessive gene on the autosome of the body. This type is rare.

2, the lack of primary lactase: also known as the lack of adult lactase, is due to human generations of eating habits leading to genetic changes, incidence is related to age and ethnicity, most people belong to this type.

3, secondary lactase deficiency: refers to the temporary lactase activity caused by intestinal epithelial damage due to various reasons, common causes such as infectious diarrhea, recovery of the body disease can return to normal.

4, for children, autumn, multiple diarrhea, bacterial diarrhea will cause a temporary low gastrointestinal function, lactase secretion decreased or decreased activity, continuous drinking milk can cause secondary lactose intolerance.

5, high-dose service of the first cell, lactam antibiotics will also cause secondary lactose intolerance.

an examination

Related inspection

Galactose tolerance test galactosemia screening

The clinical diagnosis is based on individual lactose intolerance history, clinical symptoms, stool pH and other tests. There are hydrogen breath test and lactose tolerance test, methane breath test, small intestine perfusion study, abdominal lactose-barium meal X-ray examination, stool routine test and reduction. Sugar determination, jejunal mucosal biopsy and lactase assay, 13CO2 breath test, urine test, etc.

Differential diagnosis

Differential diagnosis of congenital lactose intolerance:

1. Primary glucose malabsorption: In the primary glucose malabsorption, congenital lactase deficiency, sucrose-isomaltase deficiency, and glucose-galactose malabsorption are autosomal recessive genetic diseases, which are rare in clinic. In addition to the sucrose-isomaltase deficiency can be added to the diet after the onset of sucrose, the rest of the disease soon after birth. The histology of small intestinal mucosa biopsy was normal, and the corresponding disaccharidase activity was reduced. Glucose-galactose malabsorption and disaccharidase activity were normal. Malabsorption is caused by the congenital deficiency of Na-glucose and Na-galactose carrier protein, and the fructose absorption of the sick child is good.

2. Secondary lactase deficiency and monosaccharide malabsorption: clinically more common, because lactase is distributed at the top of the small intestine villi, all diseases that can cause damage to the intestinal mucosal epithelial cells and their brush borders can be secondary to disaccharide Lack of enzymes, severe and extensive lesions, can also affect the absorption of monosaccharides, such as acute enteritis (especially involving the upper part of the small intestine, such as rotavirus enteritis, blue giardia infection, etc.), chronic diarrhea, protein-heat card malnutrition , immunodeficiency disease, celiac disease and small bowel surgery injuries.

3. Fat malabsorption: Fat malabsorption, also known as steatorrhea, is a syndrome caused by fat digestion and malabsorption, which can be seen in many diseases such as pancreas, liver, gallbladder and intestinal diseases. The dysentery caused by intestinal lesions is accompanied by malabsorption of other nutrients, which is called malabsorption syndrome.

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