GI Malabsorption, Coeliac Disease, Nutritional Disorders

Question 1

What are causes of malabsorption?

Answer 1

Common: Coeliac, chronic pancreatitis, Crohn’s

Low bile: PBC, ileal resection, biliary obstruction, colestyramine (a medication preventing bile salt reabsorption)
Pancreatic insufficiency: pancreatic cancer, cystic fibrosis
Small bowel mucosa: Whipple disease, tropical sprue, brush border enzyme deficiencies, drugs, amyloid
Infection like giardiasis

Question 2

What are symptoms of malabsorption?

Answer 2

Diarrhoea, loss of weight, lethargy, steatorrhoea, bloating

Question 3

What are signs of deficiency?

Answer 3

Anaemia: low iron, B12, folate
Bleeding disorders: low vitamin K
Oedema: low protein
Metabolic bone disease: low vitamin D

Question 4

What tests can be used to determine GI functions?

Answer 4

Stool - Sudan stain for fat globules, stool microscopy for infection, FE-1 (elastase) reflects pancreatic exocrine function
Breath hydrogen analysis - tests for bacterial overgrowth where high end expired hydrogen indicates it
Endoscopy + small bowel biopsy

Question 5

What is tropical sprue and how is it treated?

Answer 5

Causes villous atrophy and malabsorption due to unknown causes in far and middle east + carribean. Tetracycline + folic acid used to treat.
Defined by folate deficiency and steatorrhoea so macrocytic megaloblastic anaemia, faecal fat assay being high and abnormal D-xylose test (low serum + urine levels of D-xylose after 25g oral dose)

Question 6

How would a Coeliac disease patient present?

Answer 6

Steatorrhoea, diarrhoea, abdominal pain, bloating, nausea/vomiting, apthous ulcers, angular stomatitis, loss of weight, osteomalacia

Question 7

What are risk factors for Coeliac disease?

Answer 7

family history of coeliac disease
immunoglobulin A deficiency
type 1 diabetes
autoimmune thyroid disease

Question 8

What are 1st line investigations if Coeliac suspected?

Answer 8

immunoglobulin A-tissue transglutaminase (IgA-tTG)
quantitative IgA
IgG DGP (deamidated gliadin peptide)
FBC - low Hb, low B12, low ferritin, high red cell distribution width (anisocytosis as low iron and low folate means microcytic and megaloblastic anaemia both present)

Question 9

What is a definitive diagnosis for Coeliac?

Answer 9

Duodenal biopsy: subtotal villous atrophy, increased intra-epithelial WBCs and crypt hyperplasia.
HLA genotyping may help (DQ2 most common, DQ8 potentially)

Question 10

How is Coeliac disease treated?

Answer 10

Lifelong gluten free diet and in case of crises, corticosteroids

Question 11

What skin condition is associated with Coeliac?

Answer 11

Dermatitis herpetiformis

Question 12

What is scurvy caused by?

Answer 12

Vitamin C deficiency - think poor, pregnant, odd diet

Question 13

What are signs of scurvy?

Answer 13

Listlessness, anorexia, cachexia
Gingivitis, loose teeth, halitosis
Bleeding from gums or into joints and gut
Muscle pain/weakness
Oedema

Question 14

What are wet and dry Beriberi?

Answer 14

Caused by B1 (thiamine) deficiency.
Wet: Heart failure with general oedema
Dry: Neuropathy

Question 15

How does Wernicke’s encephalopathy present?

Answer 15

Confusion, ataxia, opthalmoplegia (nystagmus, lateral rectus or conjugate gaze palsies)

Can also present with memory disturbance, hypotension, hypothermia, reduced consciousness.

Question 16

What brain damage is common in WE

Answer 16

Periacqueductal punctate haemorrhages

Question 17

What are causes of WE?

Answer 17

Chronic alcoholism, eating disorders, malnutrition, prolonged vomiting. hyperemesis gravidarum

Question 18

How is WE treated?

Answer 18

Replace B1 (if hypoglycaemia, give before glucose as giving glucose to B1 deficient patient can precipitate WE) to prevent irreversible Korsakoff’s syndrome.

Question 19

What is Korsakoff’s syndrome?

Answer 19

Hypothalamic damage and cerebral atrophy with reduced ability to create new memories and confabulation.

Question 20

What is the classical triad of pellagra?

Answer 20

Due to lack of nicotinic acid.
Diarrhoea, dementia and dermatitis (Casal’s necklace)

Question 21

What can cause pellagra and and how is it treated?

Answer 21

May occur in carcinoid syndrome, response to anti-TB drugs (isoniazid) and endemic in China + Africa.
Treated with education, electrolytes and nicotinamide.