Malabsorption Flashcards
What is malabsorption?
inadequate digestion and absorption of dietary substances due to defects in digestion, absorption, or transport. It can affect macronutrients (proteins, carbohydrates, fats), micronutrients (vitamins, minerals), or both, leading to excessive fecal excretion, nutritional deficiencies, and gastrointestinal symptoms.
What are the symptoms of malabsorption?
Symptoms of malabsorption include chronic diarrhea, steatorrhea (fatty stool), weight loss despite adequate food intake, abdominal pain, bloating, gas, and nutritional deficiencies such as vitamin and mineral deficiencies. In advanced cases, vitamin B12 deficiency may occur, while iron deficiency might be the only symptom in mild malabsorption.
How is malabsorption diagnosed?
Malabsorption can be diagnosed through a detailed patient history, blood tests to screen for consequences and causes of malabsorption, stool fat testing to confirm malabsorption if unclear, endoscopy with biopsy, and contrast x-rays. Biopsy findings may reveal specific pathologies associated with malabsorption, such as absence of villous configuration and microvilli in celiac disease, or shortened, stubby villi with modest crypt hyperplasia in tropical sprue.
What are some causes of malabsorption?
Causes of malabsorption include conditions such as celiac disease, tropical sprue, Whipple’s disease, and intestinal lymphangiectasia
What are the characteristic features and causes of celiac disease?
Celiac disease is characterized by the absence of villous configuration and microvilli, along with mild lamina propria inflammation. It is caused by an immune reaction to gluten, a protein found in wheat, barley, and rye, leading to damage in the small intestine and impaired nutrient absorption.
Describe the pathology and etiology of tropical sprue.
Tropical sprue is characterized by shortened, stubby villi and modest crypt hyperplasia in the duodenum. Its pathology may be related to factors such as infectious organisms (viral or bacterial), dietary toxins, parasitic infestations, or nutritional deficiencies like folic acid deficiency.
What are the diagnostic findings and treatment options for Whipple’s disease?
Whipple’s disease is caused by infection with Tropheryma whipplei and is diagnosed through microscopic biopsy, revealing infiltration of foamy macrophages in the lamina propria and blunting of villous structures. Treatment typically involves antibiotics targeting the causative organism.
Discuss the characteristics and diagnosis of intestinal lymphangiectasia.
Intestinal lymphangiectasia is characterized by obstruction or malformation of intramucosal lymphatics of the small bowel. Diagnosis is made through small-bowel biopsy revealing dilated lymphatic channels. This condition primarily affects children and young adults, presenting with symptoms of malabsorption, edema, and growth retardation, with treatment usually being supportive.
causes of fat malabsorption
1) Biliary system (bile duct obstruction eg liver fluke, choledocholithiasis, cholangiocarcinoma)
2) Intestinal wall (infiltration eg lymphoma, Crohn & celiac disease, CVID, amyloidosis)
3) Pancreas (exocrine insufficiency eg pancreatitis, cystic fibrosis, pancreatic lipase deficiency, pancreatic adenocarcinoma, gastrinoma)
4) Intestinal lumen (autoimmune, infectious, altered length)
5) Other eg cholestatic drugs like azathioprine, phenytoin.
Malabsorbed nutrient that causes anemia (hypochromic, microcytic)
iron
Malabsorbed nutrient that causes anemia (macrocytic)
vit, B12, folate
Malabsorbed nutrient that causes bleeding, bruising, petechiae
Vit K & C
Malabsorbed nutrient that causes Carpopedal spasm
Calcium, mg
Malabsorbed nutrient that causes EDEMA
protein
Malabsorbed nutrient that causes glossitis
Vit B2, B12, Folate, Niacin, Iron
