38. Malabsorption syndromes Flashcards Preview

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Flashcards in 38. Malabsorption syndromes Deck (51)

Malabsorption syndrome can cause

1. diarrhea
2. steatorrhea
3. weight loss
4. weakness
5. vitamin and mirenal deficiencies


Malabsorption syndromes screen for .... ( and how )

fetal fat (By Sudan stain )


Celiac disease is AKA

Gluten - sensitive enteropathy or celiac sprue


Celiac disease - mechanism ( and location )

autoimmune - mediated intolerance of gliadin ( gluten protein found in wheat ---> Th cells damage ---> decreased mucosal absorption affects distal duodenum and /or proximal jejunum ---> malabsorption + steatorrhea


associated wth / predisposition

northern European descent


Celiac disease - lab findings

1. IgA anti-tissue transglutaminase
2. IgA anti - emdomysial
3. Anti -deamidated gliadin peptide antibodies
4. IgG also present ( useful in igA deficiency)
5. bipsy --> villous atrophy , crypt hyperplaasia, intraepithelial lymphocytosis


Celiac disease -biopsy

1. villous atrophy
2. crypt hyperplasia
3. intraepthilial lymphocytosis


Celiac disease - results in / symptoms

1. malabsorption
2. steatorrhea
3. dernatis herpetiforms
4. failure to thrive ( children)
5. low bone density


Celiac disease -complications

increased risk of malignancy ( T-cell lymhoma )


Celiac disease - location of decreased mucosa absorption

distal duodenum and / or proximal jejunum


Celiac disease - treatment

gluten- free diet


D- xylose test - normally / in mucosa defects / in bacterial overgrowth

normally : passivelly absorbed in proximal small interstine --> found in urine
in mucosa defects : decreased in blood and urine
in bacterial overgrowth : decreased in blood and urine


D - xylose test pancreatic insufficiency



Lactose intolerance - mechanism

Lactase deficiency ( normally found in the brush border of enterocytes)


causes of lactose intolerance

1. congenital ( rare AR)
2. acquired ( late childhood)
3. temporary deficiency after infection


Lactose intolerance - apperance of villi

normal, except when 2ry to injury at tips of villi ( eg. viral enteritis )


Lactose intolerance - presentation

1. osmotic diarrhea with low stool ph ( colonic bacteria ferment lactose )
2. abdominal distension


Lactose intolerance - diagnosis

lactose hydrogen breath test: + for lactose malabsorption if postlactose breath hydrogen value rises more than 20 ppm compare with baseline


causes of pancreatic insuffieciency

1. chronic pancreatitis
2. cystic fibrosis
3. obstructing cancer


pancreatic insufficiency - causes / findings

- malabsorption of fat-soluble viramins ( DEKA , as well as B12)
- low duodenal pH ( biocarbonate) and fecal elastase


Tropical sprue - findings similar to celiac disease except

1. occurs in tropical regions ( eg. Carribean )
2. Arises after infectious diarrhea --. responds to antibiotics
3. decreased mucosal absorption affecting duodenum and jejunum ( like celiac ) but can involve ileum also with time


Tropical sprue - is associated with

megaloblastic anemia due to folate deficiency , and later B12 deficiency


Wipple disease - mechanism

infection with Trophyream whipplei


Trophyream whipplei - characteristics / stain

1. intracellular gram (+)
2. PAS + foamy macrophages ( lysosomes ) in interstinal lamina propria. mesenteric nodes


Wipple disease - symptoms / findings

1. Cardiac symptoms
2. Arthralgias
3. Neurologic symptoms
4. Malabsorption and steatorrhea


• A patient has diarrhea, steatorrhea, weight loss, weakness, and vitamin/mineral deficiencies; she likely suffers from what type of illness?

A malabsorption syndrome


• A child develops greasy stools and failure to thrive after the addition of wheat to her diet. She has autoantibodies to what substance?

Gluten (gliadin), suggesting celiac disease


• Celiac disease primarily affects what part(s) of the bowel?

Distal duodenum and/or proximal jejunum


• Unlike a patient with celiac disease, a patient with tropical sprue can be treated with which class of drugs?



• A patient with tropical sprue has a colonoscopy with biopsy. Which sections of the GI tract are likely to be affected?

The entire small bowel


• An 80-year-old man presents with Whipple disease. A Gram stain of the causative organism would show what?

Gram-positive rods (Tropheryma whipplei)


• A patient with suspected Whipple disease has a biopsy with PAS staining. Where would you look to confirm foamy macrophages?

Intestinal lamina propria, mesenteric lymph nodes


• A woman is diagnosed with Whipple disease and wants to know about potential complications. What non-GI symptoms might also occur?

Cardiac symptoms, Arthralgias, Neurologic symptoms (these symptoms occur mostly in older men)—think foamy whipped cream in a CAN


• What is the most common disaccharidase deficiency?

Lactase deficiency


• A boy gets diarrhea any time he eats dairy products. If he were to have an intestinal biopsy, what is the expected appearance of the villi?

Normal villi in lactase deficiency (as opposed to celiac disease, in which villi are blunted)


• A child has diarrhea and a rash on the extensor surfaces that resolves with dietary modification. It is associated with which GI pathology?

Lactose (the inability to cleave lactose via lactase causes an osmotic diarrhea)


• A patient with lactase deficiency undergoes a lactose tolerance test. Following the administration of lactose, what do you expect to see?

Osmotic diarrhea and a rise in blood glucose <20 mg/dL


• A 15-year-old boy with chronic respiratory infections due to Pseudomonas has fatty stools. What is the most likely pathophysiology?

Pancreatic insufficiency due to sludging of pancreatic secretions, as a result of cystic fibrosis


• A chronic alcoholic refuses to stop drinking. He is finally diagnosed with chronic pancreatitis. What do you expect to see on stool studies?

Neutral fat in stool (chronic pancreatitis leads to pancreatic insufficiency, fat malabsorption, steatorrhea, and findings of fat in stool)


• A patient is diagnosed with ampullary cancer. What do you expect to see on stool studies?

Steatorrhea (obstructive cancers of the pancreatic head lead to pancreatic insufficiency, causing increased neutral fat in the stool)


• Pancreatic insufficiency causes the malabsorption of which macronutrient(s)?

Fat, the fat-soluble vitamins (A, D, E, K), sometimes vitamin B12


• An 70-year-old man with arthralgias, cardiac and neurologic symptoms gets a duodenal biopsy. What is likely to be found with PAS stain?

Foamy macrophages (this is Whipple disease—remember foamy whipped cream)


• A patient with pancreatic insufficiency is given the D-xylose absorption test. What results do you observe?

Normal urinary excretion (if decreased excretion is seen, then the pathology is due to intestinal mucosa defects or bacterial overgrowth)


• A patient is said to have autoimmune damage to the small bowel caused by gluten sensitivity. What illness is described?

Celiac disease


• A child has diarrhea and a rash on the extensor surfaces that resolves with dietary modification. It is associated with which GI pathology?

Associated with celiac disease (this is dermatitis herpetiformis)


• In a patient with celiac disease, what malignancy would the patient be at increased risk for?

T-cell lymphoma


• A patient with diarrhea that occurs on a wheat-containing diet undergoes colonoscopy. What histologic findings are expected?

Blunting of villi and the presence of lymphocytes in the lamina propria (this is celiac disease)


• A patient is found to have gluten insensitivity. What is the pathophysiology of his disease?

Antibodies destroy villi (primarily in the distal duodenum and proximal jejunum), thereby decreasing mucosal absorption and causing diarrhea


• A patient has anti-endomysial, anti-tissue transglutaminase, and anti-gliadin antibodies. What serotypes are associated with this syndrome?



• A man returns from the Bahamas with complaints of diarrhea and decreased mucosal absorption. Will this patient respond to antibiotics?

The patient has tropical sprue and will respond to antibiotics


• A patient presents with extremely itchy rashes on her knees and elbows. IF shows IgA deposits at dermal papillae. How do you treat her?

A gluten-free diet will resolve the skin lesions. (this is dermatitis herpetiformis, which is a finding in celiac disease)

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