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Flashcards in Malabsorption Deck (44):
1

Define malabsorption.

Defective mucosal absorption caused by:
defective luminal digestion
mucosal disease
structural disorders

2

List some common and uncommon causes of malabsorption.

Common causes:
Coeliac disease
Crohn's disease
Post infectious
Biliary obstruction
Cirrhosis
Uncommon causes:
Pancreatic cancer
Parasites
Bacterial overgrowth
Drugs
Short bowel (including resections)

3

What are different malabsorptive states?

Protein
fat
carbohydrate
vitamins and minerals

4

List some digestive causes of protein malabsorption.

Partial or total gastrectomy (poor mixing)
Exocrine pancreatic insufficiency
Trypsinogen deficiency
Congenital deficiency of intestinal enterokinase

5

List some absorptive causes of protein malabsorption

Coeliac disease
Tropical sprue
Short bowel syndrome
Jejunoileal bypass
Defects in neutral AA transporters (Hartsnup disease)
Cystinuria I-III
Oculocerebral syndrome of Lowe

6

List some digestive causes of fat malabsorption.

Less time to mix: gastric resection, autonomic neuropathy, amyloidosis
Decreased micelle formation caused by a decreased bile acid synthesis/secretion: Cirrhosis, Biliary obstruction, CCK deficiency, small intestinal bacterial overgrowth
Decreased Lipolysis: Chronic pancreatitis, cystic fibrosis, Pancreatic/ampullary tumours, Low luminal pH, Excessive calcium ingestion, Lipase/co-lipase deficiency (rare)

7

List some absorptive causes of fat malabsorption

Decreased chylomicron formation and/or mucosal absorption:
Coeliac disease
Chylomicron retention disease

8

List some post-absorptive causes of fat malabsorption

Defective lymphatic transport:
Lymphoma
Whipple disease
Trauma

9

Name a digestive cause of carbohydrate malabsorption

alpha-amylase deficiency

10

Name some absorptive causes of carbohydrate malabsorption

Lactase deficiency
Coeliac disease
Crohn's disease
sucrase-isomaltase deficiency

11

List some causes of Vitamin B12 malabsorption

Deficiency of gastric intrinsic factor
Pancreatic insufficiency/Z-E syndrome (Reduced release of B12 from R-binding protein)
Ileal Crohn's disease
Ileal resection

12

List some causes of Folic acid malabsorption

Caused by diseases affecting the proximal small bowel
Coeliac disease
Whipple disease
Alcoholism

13

What are the fat soluble vitamins?
What could cause malabsorption of these?

Vitamins A, D, E and K
Anything that disrupts fat absorption will result in one or more than one deficiency

14

What are the clinical features of lactose malabsorption (i.e. lactase deficiency)

History of the induction of the diarrhoea, abdominal discomfort and flatulence following the ingestion of dairy products.

15

How is lactase deficiency diagnosed?

It is diagnosed clinically, and confirmed using the lactose breath hydrogen test, or the oral lactose intolerance test.

16

What is tropical sprue?

Colonisation of the intestine by an infectious agent or alterations in the intestinal bacterial flora induced by the exposure to another environmental agent.

17

What are the clinical features of tropical sprue?

Diarrhoea
Steatorrhoea
Weight loss
Nausea
Anaemia

18

What is the treatment for tropical sprue?

Tetracycline + folic acid

19

What is whipple's disease?

A rare infectious bacterial disease caused by Tropheryma whipplei.
There is multi-system involvement and increase in the frequency of HLA-B27.

20

What are the clinical features of whipple's disease?

Weight loss, diarrhoea, steatorrhea, abdominal distension, arthritis, fever, nutritional deficiency symptoms

21

How is whipple's disease diagnosed?

Biopsy and demonstration of T.whipplei in involved tissues by microscopy

22

What is the treatment for Whipple's disease?

Anti-microbial

23

What are the clinical features of Crohn's disease?

Abdominal pain and diarrhoea
Fever and weight loss
Abdominal tenderness, most commonly in the right lower quadrant

24

How is Crohn's disease diagnosed?

Endoscopy
Barium imaging of small bowel mucosal disease, including strictures, ulcerations and fistulae
CT
MRI

25

What is the treatment for Crohn's disease?

Steroids, immunosuppressants (azathioprine), biological therapy (anti-TNF)

26

What does Giardia lamblia/ giardia intestinalis cause?
What are risk factors for contracting this parasitic infection?
What are other intestinal parasites?

Giardiasis
Risk factors are travel to areas where the water supply may be contaminated and swimming in ponds
Other parasites: Coccidial, strongyloides

27

What are the clinical features of giardiasis?

Diarrhoea
Flutulence
Abdominal cramps
Epigastric pain
nausea
Significant malabsorption with steatorrhoea and weight loss may develop

28

How is giardia lamblia confirmed in the lab?

Stool examination for ova and parasites
Three separate stool samples increases the yield of positive examinations to 80-90%

29

How is giardiasis treated?

Metronidazole for 1 week

30

Which pathogens cause small bowel overgrowth?

E. coli or Bacteroides.

31

What are the symptoms of small bowel overgrowth?

Diarrhoea, steatorrhoea and macrocytic anaemia

32

What lab results would be found in small bowel overgrowth?

low cobalamin and high folate levels.
aerobic and or anaerobic colonic-type bacteria in a jejunal aspirate obtained by intubation

33

What is the treatment for small bowel overgrowth?

Surgical correction of an anatomical blind loop
Tetracyclines 2-3 weeks

34

In which known disease states should you suspect malabsorption?

Those of the liver, pancreas and small bowel

35

What features of past medical history should make you suspect malabsorption?

Gastric or small bowel resection
Gastrointestinal diversion (bariatric)
Radiation exposure
Travel

36

What questions should you ask about diarrhoea?

Duration
Malabsorptive stool
Fat globules
Floating
Hard to flush away
Offensive

37

What is easy bruising a sign of?

Vitamin C "scurvy" (deficiency)
VItamin K deficiency

38

Name an autosomal recessive skin condition due to impaired zinc uptake.
What are the signs of this?
How is this treated?

Acrodermatitis Enteropathica.
The signs are a perioral or acral rash, and alopecia.
It is treated with lifelong zinc supplements.

39

Which skin condition may indicate coeliac disease?
How does it present?
What causes it?

Dermatitis herpetiformis.
It presents as itchy blisters on extensor surfaces.
It is caused by sub-epithelial IgA deposition.

40

What can glossitis and angular stomatitis be signs of?

Vitamin B deficiency
Iron deficiency

41

What can spooned nails be a sign of?

Iron deficiency

42

Which baseline investigations should be carried out?

FBC
Coagulation
LFTs
Albumin
Calcium/Magnesium
Stool culture

43

Which anatomical investigations can be done?

Endoscopy
Imaging

44

What should the management of a malabsorption be?

Treat the underlying cause
Replace the deficiency
Support nutritionally

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