Dr. Adnan Hamawandi Professor of Pediatrics Malabsorption Dr. Adnan Hamawandi Professor of Pediatrics

Malabsorption Malabsorptive disorders are conditions that cause insufficient assimilation of ingested nutrients as a result of either maldigestion or malsbsorption.

Malabsorption Causes Generalized defect: present with similar signs and symptoms; abdominal distention; pale, foul smelling, bulky stools; muscle wasting; poor weight gain or weight loss; and growth retardation. A. Exocrine pancreas: cystic fibrosis, chronic pancreatitis, chronic protein calorie malnutrition, Shwachmann-Diamond syndrome.

Malabsorption B. Liver: biliary atresia, familial neonatal hepatitis, other cholestatic states. C. Intestine: massive resection, giardiasis, celiac disease, cow milk protein intolerance, immune deficiency, tropical sprue. Specific defect: the clinical features of these disorders typically differ from those of generalized malabsorptive disorders, some present without gastrointestinal disorders.

Malabsorption A. Intestinal: abetalipoproteinemia, Hartnup disease, disaccharidase deficiency, vit.B12 malabsorption, glucose - galactose malsbsorption, Chloride losing diarrhea, acrodermatitis enteropathica. B. Drug induced: sulfasalazine(folate), phenytoin (Calcium) C. Pancreatic: Specific enzyme deficiency like lipase, trypsinogen.

Celiac disease Gluten sensitive enteropathy Environmental, genetic, and immunologic factors, some of which are clear and others that are only now beginning to come into focus, are important in the pathogenesis of celiac disease. The disease activating proteins in wheat, rye, and barely widely termed Glutens. Celiac disease is strongly associated with HLA class II genes on DQ locus. DQ2 &DQ8.

Celiac disease Gluten sensitive enteropathy When susceptible individuals ingest gluten, the antigen presenting cells can potentially bind the gluten peptides and present them to DQ2 or DQ8 restricted CD4+ T cells in the small intestinal mucosa. The later release gamma interferon and activate the release of metalloproteinases that can damage the intestinal mucosa.

Celiac disease Clinical features Most children show symptoms between nine and 24 months , but the condition may occur at any age. Malabsorption causing diarrhea, failure to thrive, abdominal distention, and muscle wasting is the classic presentation. Also seen are vomiting, anorexia, irritability, isolated abdominal distention, short stature, unexplained iron deficiency anemia, rickets, glossitis and angular stomatitis.

Celiac disease Diagnosis Serological screening: antiendomyseal IgA and IgG antibodies are recommended. Antigliadin and Antireticulin antibodies can also be of help. If serological screening is positive a small bowel biopsy should be performed. Demonstration of inflammation, villous atrophy and crypt hyperplasia is consistent with the diagnosis. ”Marsh classification”

Celiac disease Therapy Dietary: Life long provision of gluten free diet. All wheat, rye, and barely should be eliminated from the diet. Initially while small intestinal mucosa heal, restriction of lactose as well as vitamin and iron supplementation may be necessary. Improvement of mood and appetite is followed by lessening of diarrhea usually within 1 week of starting therapy.

Celiac disease Prognosis Diabetes mellitus, IgA deficiency, and other autoimmune disease have high incidence among celiac patients. The late development of bowel lymphoma in long standing cases with poor adherence to diet is possible. No complications from long term gluten free diet treatment are recognized.

Cow milk protein allergy The precise mode by which cow’s milk protein cause disease is unknown. Sensitization may occur de novo or after a bout of acute infectious enteritis. Variable mucosal abnormalities may be found in the stomach, small bowel, and colon. Infants who are sensitive to cow’s milk protein may also be sensitive to soy protein.

Cow milk protein allergy Clinical features Most symptoms develop in the first 3 months of life. 1. Diarrhea and vomiting are the most common and if prolonged lead to failure to thrive. 2. Rectal bleeding may be seen if allergic colitis occur. 3. Edema secondary to protein losing enteropathy, often associated with anemia. 4. Wheezing, rhinorrhea, and eczema may occur.

Cow milk protein allergy Diagnosis is usually made empirically once symptoms resolve after elimination of cow’s milk. Therapy: elimination of cow’s milk from the diet is usually curative although severely affected infants may take weeks or months to recover and may require IV alimentation until the intestinal mucosa heals.

Lactose intolerance Lactase deficiency Lactose enzyme located on the brush border membrane of the small bowel epithelial cells, hydrolyses lactose into glucose and galactose before their absorption. If this hydrolysis is incomplete the sugar will accumulate in the distal intestinal lumen where organic acids and hydrogen gas are produced by bacteria.

Lactose intolerance Lactase deficiency The excess intraluminal sugar and organic acids draw water into the lumen leading to osmotic diarrhea. Lactase deficiency is a common cause of diarrhea in childhood. Congenital absence of lactase is rare while acquired lactase deficiency is usually secondary to a diffuse mucosal disease like infectious diarrhea or celiac disease.

Lactose intolerance Clinical manifestations In response to ingestion of lactose (milk) Explosive watery diarrhea is associated with abdominal distention, borborygmi, flatulence, cramping abdominal pain, and an excoriated diaper area.

Lactose intolerance Diagnosis 1. Breath hydrogen testing; is the most accurate diagnostic test. 2. Stool PH; less than 5.6 and presence of reducing substance + 2 and more suggest carbohydrate malabsorption. 3. Intestinal biopsy; Direct assay of brush border enzyme activity.

Lactose intolerance Therapy 1. Elimination of cow’s milk and substitution by lactose free milk. 2. Lactaid is a lactase preparation when added to milk it allows asymptomatic consumption of modest quantities of milk incubated with the added enzyme.