Abdominal Flashcards
Mass in Wilm’s tumour
Renal, sometimes visible, doesn’t cross midline
Mass in neuroblastoma
Irregular, firm, may cross midline, child usually very unwell
What is the most common cause of liver failure in children?
Biliary atresia
What is the main indication for liver transplant in children?
Biliary atresia
What other anomalies is biliary atresia associated with?
Cardiac defects Polysplenia IVC abnormalities Pre-duodenal portal vein Situs inversus Malrotation
What is biliary atresia?
Destruction or absence of extrahepatic and intrahepatic bile ducts, causing cholestasis, fibrosis and cirrhosis
How does biliary atresia present?
Jaundice and failure to thrive
What is the management for biliary atresia?
Kasai procedure
Low dose antibiotics to prevent cholangitis
Nutritional support
What is the Kasai procedure?
Portoenterostomy: removal of the fibroses biliary tree and formation of a Roux-en-Y anastomosis where a loop of jejunum is anastomosed to the cut surface of th ports hepatic, facilitating drainage of bile from any remaining patent ductules
When should a Kasai procedure be done?
ASAP - only usually successful if done before 60 days
What are the complications of biliary atresia?
Recurrent cholangitis
Cirrhosis
Portal hypertension
What is the prognosis of biliary atresia?
<20% survive long term with their own liver
What are the types of biliary atresia?
I - obliteration of CBD
II - CBD and common hepatic duct
III - most common - entire extra hepatic biliary tree
What are the tests of liver synthetic function?
Albumin, PT, INR
What are the tests of biliary excretion?
Total and direct bilirubin
What are the tests of cholestasis?
GGT, ALP
What are the tests of hepatocellular damage?
AST and ALT
Where is AST produced?
Cytosol and mitochondria of the liver, heart, skeletal muscle, kidney, pancreas, and red cells
Where is ALT produced?
Cytosol of liver and muscle cells
What does an ALT:AST ratio >1 suggest?
Fibrosis
What does ALP reflect?
Biliary epithelial damage
What is Gilbert syndrome?
A mild deficiency of UGT activity
What is the cause of Gilbert syndrome?
Polymorphism with TA repeats in the TATA box in white people; exon mutations in Asian individuals on 2q37
How common is Gilbert syndrome?
7% of the population
What is Crigler-Najjar type II?
Moderate UGT deficiency
What is Crigler-Najjar type 1?
Severe UGT deficiency
How are Gilbert and Crigler-Najjar inherited?
Autosomal recessive, although Gilbert and Crigler-Najjar type II can be autosomal dominant
How is Alagille syndrome inherited?
Autosomal dominant
What are the features of Alagille syndrome?
Intrahepatic biliary hypoplasia Facial dysmorphism Cardiac defects Renal abnormalities Butterfly vertebrae Ocular anomalies Pancreatic insufficiency Craniosynostosis Neurovascular abnormalities Delayed gross motor milestones
What are the facial features of Alagille?
Wide forehead Deep set eyes Long straight eyes Prominent chin Small, low-set ears
What are the cardiac defects of Alagille?
Peripheral pulmonary artery stenosis
Right sided defects
Septal defects
What are the ocular anomalies in Alagille?
Posterior embryotoxon, causing peripheral corneal opacification
What are the neurovascular abnormalities in Alagille?
Basilar artery anomalies and others
What are the genes associated with Alagille?
JAG1 on 20p12 and the NOTCH2 gene
How does Alagille syndrome present?
Neonatal jaundice Cholestasis Pruritus Xanthomata Failure to thrive
What is the prognosis in Alagille?
50% regain normal liver function by adolescence; 15% need transplant
How is Alagille managed?
Urso (increases volume of bile) Cholestyramine (bile acid sequestrant) Rifampicin and naltrexone for itching Surgery Transplant
What surgeries can be done for Alagille?
Partial external biliary diversion
Ileal exclusion
What are the general features of progressive familial intrahepatic cholestasis?
Presents with neonatal hepatitis, pruritus, faltering growth and progressive liver disease needing transplantation in the first few years of life
What is type 1 progressive familial intrahepatic cholestasis also known as?
Byler disease
What causes Byler disease?
Mutation of FIC1 gene on 18q21-22
What are the features of Byler disease?
Pancreatitis
Persistent diarrhoea
Short stature
Sensorineural hearing loss
What will investigations show in Byler disease?
Normal GGT and cholesterol
Elevated serum bile salts and sweat chloride
Low chenodeoxycholic acid in bile
What causes type 2 progressive familial intrahepatic cholestasis?
Mutations on chromosome 2q24, the bile salt export pump gene
What will the GGT be in type 2 progressive familial intrahepatic cholestasis?
Normal
What causes type 3 progressive familial intrahepatic cholestasis?
Mutations in the P-glycoprotine MDR-3 gene (ABCB4)
What are the lab findings in type 3 progressive familial intrahepatic cholestasis?
Elevated GGT
Bile phospholipids 15% normal
How is Alpha1-antitrypsin deficiency inherited?
Autosomal recessive
What causes Alpha1-antitrypsin deficiency liver disease?
PiZZ phenotype of the protease inhibitor on chromosome 14
When might Alpha1-antitrypsin levels be normal in Alpha1-antitrypsin deficiency and why?
Inflammatory illnesses - because it is an acute phase reactant
What does Alpha1-antitrypsin do?
Neutralises neutrophil elastase and prevents inflammation and tissue damage in the lung
How does Alpha1-antitrypsin deficiency cause liver disease?
Abnormal folding of the mutated alpha-1-antitrypsin molecule causes it to become trapped in the endoplasmic reticulum
How does Alpha1-antitrypsin deficiency liver disease present?
Prolonged neonatal conjugated jaundice Acholic stools Bleeding due to vit K deficiency Hepatomegaly Splenomegaly develops with cirrhosis and portal hypertension
What is the prognosis of Alpha1-antitrypsin deficiency?
50% good prognosis, the others develop liver disease and need transplantation
How is tyrosinaemia type 1 inherited?
Autosomal recessive -gene is located on chromosome 15
What is the pathophysiology of tyrosinaemia type 1?
Deficiency of fumarlyacetoacetate hydroxylase, which prevents metabolism of tyrosine - toxic metabolites then accumulate and damage the liver, kidneys, heart and brain
How does tyrosinaemia type 1 present?
Infants with acute liver failure
Older children with chronic lung disease
How is tyrosinaemia type 1 diagnosed?
Succinylacetone in the urine
Increased plasma tyrosine, phenylalanine, and methionine
Newborn screening
How is tyrosinaemia type 1 managed?
Low protein diet
Vitamin D
Nitisinon which prevents formation of toxic metabolites, reverses damage
How is hereditary fructose intolerance inherited?
Autosomal recessive - abnormal gene is on chromosome 9
What causes the fructose intolerance in hereditary fructose intolerance?
The affected gene codes for fructose-bisphosphate aldolase, which catalyses the cleavage of fructose
How does hereditary fructose intolerance present?
Fatty liver Refusal to eat sweet foods Neonatal hypoglycaemia and lactic acidosis Cirrhosis Failure to thrive GI bleeding Hypoglycaemia attacks Vomiting Seizures Proximal renal tubular acidosis
What will lab tests show in hereditary fructose intolerance?
Fructosaemia High bili and magnesium Low phosphate Glycosuria Phosphaturia Bicarbonaturia High urinary pH
How is hereditary fructose intolerance managed?
Avoiding fructose and fasting, particularly during febrile episodes
What are some complications of chronic hepatitis?
Hypersplenism Encephalopathy Oesophageal varices Portal hypertension Protein calorie malnutrition Ascites Thrombosis of portal vein SBP Coagulopathy Hepatocellular carcinoma
What is the pathophysiology of hepatic encephalopathy?
Portosystemic shunting - neurotoxic metabolites from the gut are shunted around the cirrhotic liver rather than being removed by the liver
Altered blood brain barrier (more permeable)
Toxic metabolic then affect the CNS
What is the first stage of hepatic encephalopathy?
Prodrome: slow mentation, slight asterixis, minimal EEG change
What is the second stage of hepatic encephalopathy?
Impending compa - disorientation, drowsiness, slowing on EEG
What is the third stage of hepatic encephalopathy?
Stupor - very sleepy, confused, delirious, asterixis, grossly abnormal EEG
What is the fourth stage of hepatic encephalopathy?
Loss of consciousness, decorticate or decerebrate posturing, no asterixis, EEG shows delta waves and decreased amplitudes
How is hepatic encephalopathy managed?
Decrease nitrogenous load to the bowel Reduce bacterial production of ammonia in the colon Review precipitating factors Restrict protein Consider BCAAs Lactulose Neomycin
What is TIPSS?
Can be used for vatical bleeding - a transjugular intrahepatic portosystemic stent shunt
What is the triad of hepatopulmonary syndrome?
Liver dysfunction
Intrapulmonary arteriovenous shunts
Arterial hypoxaemia
What are the features of hepatorenal syndrome?
Oliguria Factorial excretion of sodium <1% Urine plasma:creatinine <10 Low GFR and raised creatinine Absence of hypovolaemia
How is chronic hepatitis managed?
Nutritional support Vitamin supplementation Sodium restriction Dialysis Urso Control of bleeding
Which antibodies might be present in autoimmune hepatitis?
Type 1: ANA, anti smooth muscle
Type 2: LKM-1
How is autoimmune hepatitis managed?
Steroids
Azathioprine
Liver transplant
What is the most common form of acute viral hepatitis?
Hep A
What kind of virus is hepatitis A?
Picornavirus - RNA
How does hep A spread?
Orofaecal
What is the incubation period for hep A?
2-6 weeks - infectivity begins during the prodromal phase, peaks at start of symptoms, then rapidly declines. Shedding can persist for 3 months
How does hep A present?
Usually asymptomatic, especially in younger people
What is the mortality rate for hep A and who is most at risk?
0.2-0.4% symptomatic cases, particularly <5 or >50 years
What are the complications of hep A?
Liver failure Prolonged cholestasis Extrahepatic complications Recurrent hepatitis Neurological involvement e.g. GBS Renal disease Acute pancreatitis Haematological disorders
How is hep A diagnosed?
Anti-HAV IgM indicates recent infection, peaks in acute illness and persists for 4-6 months
anti-HAV IgG appears early and persists lifelong
How is hep A managed?
Supportively + hydration
How long does it take to recover from hep A?
3-6 months
What protection does hep A IVIG offer?
6 months of protection, if given within 2-3 weeks of exposure
What is the worldwide prevalence of hep B carriage?
5%
How is hep B transmitted?
Perinatally, or horizontally via parenteral/sexual/environment
What is the risk of vertical transmission of hep B in HBeAg positive mothers?
70-90%
What are the possible outcomes of hep B infection?
Symptomatic acute hep B (resolves with immunity)
Asymptomatic chronic infection
How is chronic hep B infection defined?
HBsAg positive for at least 6 months
How many people with chronic hep B infection will get chronic liver disease as a result?
90%
What are the stages of chronic hep B infection?
Immune tolerance
Immune clearance
Residual non-replicative infection
What are the complications of chronic hep B infection?
Cirrhosis and hepatocellular carcinoma
In hep B, what does positive IgG and IgM core antibodies, surface antigen, and e antigen indicate?
Acute infection
In hep B, what does core antibody, surface antigen, and e antigen positivity indicate?
Chronic infection
How is hep B treated?
Interferon gamma
Pegylated interferon
Lamivudine, famiciclovir, adefovir
How many patients with hep B seroconvert with therapy?
50%
How is hep C transmitted?
blood products, occasionally vertical
How does hep C present?
Usually asymptomatic, but can lead to cirrhosis
How is hep C diagnosed?
Anti-HCV positive, HCV RNA positive in 2 consecutive samples
How is hep C managed?
Interferon alpha
Ribavirin
How many hep C patients seroconvert with therapy?
70%
What is the main cause of graft dysfunction following liver transplant?
Graft rejection
When does graft rejection in liver transplant commonly occur?
First 3 months
Which patients less commonly get liver graft rejection?
Children under 6 months, those receiving a live donor graft
How does late-acute liver graft rejection present?
Raised transaminases, fever, malaise, jaundice
How is late-acute liver graft rejection managed?
Pulsed steroids
Increased calcineurin inhibitors
Introduction of another immunosuppressant e.g. MMF
Anti T cell antibodies
How is chronic liver transplant rejection defined?
Loss of >50% of bile ducts
When does chronic liver graft rejection occur?
6 weeks to 6 months post transplant
What are the complications of chronic liver graft rejection?
Biliary strictures
Cholangitis
Cholestasis
How is chronic liver graft rejection managed?
Optimise immunosuppression
Dilatation of strictures
Retransplantation if severe
What kind of infections are patients at risk of post-liver transplant?
up to 1 month post: bacterial or viral
2-6 months post: viral e.g. CMV, EBV
What biliary complications can arise post liver transplant?
Cholangitis due to intrahepatic or extra hepatic strictures
What hepatic vascular complications can arise post liver transplant?
Hepatic artery, vein or portal vein stenosis or occlusion
What is post-liver-transplant lymphoproliferative disorder?
EBV-driven B cell proliferation, ranging from lymphohyperplasia to true lymphoma
When does post-liver-transplant lymphoproliferative disorder occur?
3-12 months post transplant
What are the risk factors for post-liver-transplant lymphoproliferative disorder?
EBV or CMV infection
Younger age
Immunosuppression
What are the long term toxicities of calcineurin inhibitors?
Nephrotoxicity
Hypertension
Neurotoxicity
Hyperlipidaemia
What are the side effects of calcineurin inhibitors?
Hypertrichosis
Gum hyperplasia
What do calcineurin inhibitors do?
Inhibit production of cytotoxic T-lymphocytes and IL-2
How is Wilson disease inherited?
Autosomal recessive
What is the pathophysiology of Wilson disease?
Reduced synthesis of caeruloplasmin, the copper binding protein, leads to defective excretion of copper in bile, and accumulation of copper in the liver, brain, kidney and cornea
When does Wilson disease present?
Older children - rarely under 3
How does Wilson disease present?
Liver disease in younger children, neuropsychiatric features in older children
What are some extrahepatic features of Wilson disease?
Renal tubular dysfunction
Vitamin D resistant rickets
Haemolytic anaemia
Sunflower cataracts
How is Wilson disease diagnosed?
Low serum caeruloplasmin and copper Increased urinary copper Kayser-Fleischer rings Elevated hepatic copper on liver biopsy Gene testing
How is Wilson disease treated?
Penicillamine or Trientine, which both promote urinary copper excretion
Zinc reduces copper absorption
Pyridoxine prevents peripheral neuropathy
What stool markers can be tested in inflammatory bowel disease?
Alpha-1-antitrypsin
Faecal calprotectin
MC+S
What is the value of stool markers in IBD?
Measure of mucosal inflammation
What FBC abnormality is often seen in Crohn’s disease?
Leucocytosis
In which of Crohn’s and UC is CRP more likely to be elevated?
Crohn’s
Which infection can mimic inflammatory bowel disease and with which features?
Yersinia - colitis, erythema nodosum, and arthralgia
Also TB
What will the endoscopy findings be in UC?
Oedematous, hyperaemic and friable mucosa
What will the endoscopy findings be in Crohn’s?
Aphthous or serpiginous ulcers, erythema, skip lesions, cobblestone mucosa
What is the name of the rare fatal lymphoma associated with IBD patients exposed to biologics or immunomodulators?
Hepatosplenic T cell lymphoma
What is coeliac disease?
A specific T-lymphocyte intolerance of gluten
Which conditions show elevated incidence of coeliac?
Down Turner T1DM Addison IgA
What is the gold standard for diagnosis of coeliac disease?
Small bowel biopsy
What will a small bowel biopsy show in coeliac disease?
Partial or complete villous atrophy
Crypt hyperplasia
Increased intraepithelial lymphocytes
What serology can be sent for coeliac disease?
Anti TTG IgA
Anti endomysial antibodies
Which HLA types are associated with coeliac disease?
HLA-DQ2 and HLA-DQ8
Which skin/mucosal features are associated with coeliac disease?
Dermatitis herpetiformis
Recurrent aphthous stomatitis
Which children should be screened for coeliac disease?
Autoimmune thyroid T1DM IBS Dermatitis herpetiformis 1st degree relative affected HLA matched siblings Monozygotic twins
What are the dietary sources of iron?
cereals, red meat, fresh fruit, green vegetables
Where is iron absorbed?
Proximal small bowel
What kind of anaemia does iron deficiency cause?
Hypochromic microcytic
What do iron studies show in IDA?
Low serum iron and high transferrin
What are the dietary sources of folate?
liver, green vegetables, cereals, orange, milk, yeast, mushrooms
Where is folate absorbed?
Proximal small bowel
What does folate deficiency cause?
Megaloblastic anaemia, poor weight gain, chronic diarrhoea, thrombocytopenia
How do you test for folate status?
Serum folate reflects recent changes
Red cell folate indicates total body stores
What are the dietary sources of vitamin B12?
Foods of animal origin
Where is B12 absorbed?
Terminal ileum
What facilitates B12 absorption?
Intrinsic factor
What lab abnormalities does B12 deficiency cause?
Megaloblastic anaemia
Increased methylmalonic acid in urine
What are the clinical features of B12 deficiency?
Glossitis
Peripheral neuropathy
Subacute combined degeneration of the cord
Optic atrophy
What do you need to supplement B12 with, other than B12?
Folic acid
What are the dietary sources of zinc?
beef, liver, eggs, nuts
What are the clinical features of zinc deficiency?
Anaemia Growth retardation Periorofacial dermatitis Immune deficiency Diarrhoea
What is acrodermatitis enteropathica?
Autosomal recessive condition with impaired gut absorption of zinc
What are the clinical features of acrodermatitis enteropathica?
Those of zinc deficiency plus reddish tinted hair with alopecia Candidal infection Paronychia and dystrohpic nails Poor wound healing Ocular changes
What is the treatment for acrodermatitis enteropathica?
Zinc supplementation
What are the effects of vitamin A deficiency
Night blindness Poor growth Xerophthalmia Follicular hyperplasia Impaired resistance to infection
What are the effects of excess vitamin A?
Carotenaemia Hyperostosis with bone pain Hepatomegaly Alopecia Desquamation of palms Raised ICP in acute intoxication
What are the dietary sources of vitamin A?
Milk, fat, fruit and vegetables, eggs, liver
What function does vitamin E serve?
Antioxidant
What are the dietary sources of vitamin E?
Green vegetables and vegetable oil
What are the effects of vitamin E deficiency?
Ataxia
Peripheral neuropathy
Retinitis pigmentosa
How is abetalipoproteinaemia inherited?
Autosomal recessive
What is the pathophysiology of abetalipoproteinaemia?
Failure of chylomicron formation with impaired absorption of long-chain fats with fat retention in the enterocyte
How does abetalipoproteinaemia present?
Faltering growth
Abdominal distension
Foul smelling, bulky stools
Symptoms of vit E deficiency
How is abetalipoproteinaemia diagnosed?
Low serum cholesterol
Very low plasma triglycerides
Acanthocytes on peripheral blood film
Absence of betalipoprotein in the plasma
How is abetalipoproteinaemia treated?
Sub medium chain triglycerides for long chain, as these are absorbed via the portal vein rather than the thoracic duct
High doses of fat soluble vitamins
What is vitamin D needed for?
Calcium homeostasis and bone growth
What are the sources of vitamin D?
fish oil, vegetable oil, skin synthesis by UVB light, egg yolks
What re the two main forms of vitamin D?
Ergocalciferol (D2)
Cholecalciferol (D3)
Where does ergocalciferol come from?
Irradiated fungi e.g. yeast
What has to happen to vitamin D to become active?
2 sequential hydroxylations - to 25-dydroxyvitamin D in the liver, then 1,25-dihydroxyvitamin D in the kidney
What are the clinical features of vitamin D deficiency?
Rickets Impaired bone growth and formation Bowing of long bones Enamel hypoplasia Kyphoscoliosis Pelvic deformity
What are the biochemical features of vitamin D deficiency?
Decreased calcium absorption
Low plasma calcium
High ALP
Raised PTH
What is the most accurate measure of body vitamin D levels?
Serum 25-hydroxyvitamin D
What are the dietary sources of vitamin K?
cows’ milk, green leafy vegetables, pork, very little in breast milk
What does vitamin K deficiency cause in newborns?
Haemorrhagic disease of the newborn
What are the clinical features of haemorrhagic disease of the newborn?
Bleeding from umbilical stump Haematemesis and melaena Epistaxis Excessive bleeding from puncture sites Intracranial bleeding
When does haemorrhagic disease of the newborn usually present?
Day 2 or 3
How is haemorrhagic disease of the newborn diagnosed?
Prolonged prothrombin and partial thromboplastin times
Normal thrombin time and fibrinogen
How does cow’s milk protein intolerance present?
Vomiting, diarrhoea, colic, constipation
Less commonly: respiratory symptoms, dermatological, behavioural
How is cow’s milk protein intolerance diagnosed?
Clinically - skin prick and IgE RAST not always helpful
How many children with cow’s milk protein intolerance will be able to go back to a normal diet?
80-90% by third birthday
What causes sucrose-isomaltase deficiency?
Lack of enzyme required for hydrolysis of sucrose and alpha-limit dextrins in small intestine
What are the symptoms of sucrose-isomaltase deficiency?
Watery diarrhoea and/or faltering growth when complex carbohydrates are introduced; symptoms may be mild
How is sucrose-isomaltase deficiency diagnosed?
Reducing substances in stool negative, diagnosis is confirmed with stool chromatography
What are some acquired causes of disaccharide malabsorption?
Post-enteritis
Post neonatal surgery
Malnutrition
Late-onset lactose intolerance
Which is more common, congenital or late-onset lactose intolerance?
Late-onset
What is the problem in late-onset lactose intolerance?
Deficiency of lactase (brush border enzyme)
How does late-onset lactose intolerance present?
Explosive stools
How is late-onset lactose intolerance diagnosed?
Stool chromatography, reducing substances in the stool
How is glucose-galactose malabsorption inherited?
Autosomal recessive
How does glucose-galactose malabsorption present?
Rapid-onset watery diarrhoea from birth
How is glucose-galactose malabsorption diagnosed?
Clinically, but reducing substances in stool will be positive. Responds to stopping glucose, and relapses when it’s reintroduced.
How is glucose-galactose malabsorption treated?
Use fructose as main carbohydrate instead
What does hydrogen breath testing look for?
Carbohydrate malabsorption
How does hydrogen breath testing work?
Malabsorbed carbohydrate should pass to the colon and be metabolised by bacteria, releasing hydrogen gas which is absorbed and released in breath
How does congenital microvillous atrophy present?
Intractable diarrhoea with poor weight gain from birth; poor tolerance of even minimal enteral intake
What is the prognosis for congenital microvillous atrophy?
Poor survival rate with long term PN dependence. Can be cured by intestinal transplant
What is the pathophysiology of tufting enteropathy?
Primary intestinal epithelial dysplasia with presence of ‘tufts’ of extruding epithelial cells on biopsy
What is the prognosis in tufting enteropathy?
PN dependent in early life but intestinal function can improve with age
Which problems are associated with tufting enteropathy?
Choanal atresia Oesophageal disease Imperforate anus Short stature Delayed bone age Punctate keratitis
How is congenital chloride diarrhoea inherited?
Autosomal recessive
How does congenital chloride diarrhoea present?
Severe watery diarrhoea present at birth, history of polyhydramnios
What is the defect in congenital chloride diarrhoea?
Failure of chloride reabsorption in exchange for bicarbonate in the ileum
What are the lab findings in congenital chloride diarrhoea?
Serum sodium and chloride are low with metabolic alkalosis
Stool pH and chloride are high
How is congenital chloride diarrhoea treated?
Sodium and potassium chloride supplements
What is the prognosis for congenital chloride diarrhoea?
Good if diagnosed early
How is giardiasis diagnosed?
Stool examination for cysts or examination of duodenal aspirate on endoscopy
How is giardiasis treated?
Metronidazole
What faecal elastase level suggests exocrine pancreatic insufficiency?
<150ug/g
What might cause a false positive faecal elastics result?
Watery stool
How is Schwachman-Bodian-Diamond syndrome inherited?
Autosomal recessive
What is the gene for Schwachman-Bodian-Diamond syndrome?
7q11
What are the main features of Schwachman-Bodian-Diamond syndrome?
Pancreatic insufficiency Neutropenia Short stature Metaphyseal dysostosis Hepatic dysfunction Increased frequency of infections Haematological abnormalities
How does bowel bacterial overgrowth present?
Steatorrhoea and fat-soluble vitamin deficiency
What are the risk factors for bowel bacterial overgrowth?
Previous GI surgery Strictures Short bowel syndrome Loss of ileo-caecal valve Repeated courses of antibiotics
What is the first choice antibiotic for bowel bacterial overgrowth?
Metronidazole
What is the defect in intestinal lymphangiectasia?
Functional obstruction of lymph flow through the thoracic duct and into the IVC
How does intestinal lymphangiectasia present?
Fat malabsorption and protein-losing enteropathy
Intestinal lymphangiectasia can be secondary to which diseases?
Pancreatitis
Pericarditis
Post-fontan
Malignancy
What will a small bowel biopsy show in intestinal lymphangiectasia?
Patchy areas of dilated lymphatics in absence of other pathology
What is the treatment for intestinal lymphangiectasia?
Medium chain triglycerides, which are absorbed directly into the portal vein
Is paediatric Crohn’s more or less aggressive than adult?
More
Where in the gut does Crohn’s affect?
Anywhere from mouth to anus
How common is stricturing/penetrating disease in Crohn’s?
25% within 4 years of presentation
What are the features which are specific to Crohn’s vs UC?
Panenteric Skip lesions Transmural Granulomas Perianal disease
What is the best intervention for remission induction in Crohn’s?
EEN (exclusive enteral nutrition) with elemental or polymeric diet
What are the medication options for remission induction in Crohn’s?
Steroids
Infliximab
Adalimumab
What is infliximab?
Chimeric monoclonal anti-TNF-antibody
What is the mechanism of action of infliximab?
Binds to soluble TNF alpha and its precursor, neutralising their actions
How might Crohn’s patients become resistant to infliximab?
20% develop antibodies; can reduce the chance of this by also giving immunomodulators
What is adalimumab?
Monoclonal anti TNF alpha antibody
What are the side effects of anti TNF alpha antibodies?
Autoimmune like syndromes Malignancy Pancytopenia Liver dysfunction Eczema and psoriasis Heart failure Infusion and injection site reactions Neurological syndromes
What are the options for maintenance of Crohn’s disease?
Immunomodulators
Methotrexate
Biologics
Which immunomodulators are used in Crohn’s disease?
6-mercaptopurine, azathioprine
What might you want to test before starting 6-marcaptopurine in Crohn’s disease?
TPMT activity - reduced in some, which can lead to metabolising to thioguanine instead of 6-MMP, which is toxic in excess
What are the side effects of methotrexate?
Nausea Anorexia Stomatitis Diarrhoea Headache Dizziness Fatigue Altered mood
What can reduce the side effects of methotrexate?
Folic acid supplementation
What are the features specific to UC vs Crohn’s?
Colon only
Crypt abscesses
What are the first line drugs for mild/distal UC?
Oral and rectal sulfasalazine or mesalazine
What screening should children with UC have?
Endoscopies - higher risk of colonic malignancies
When is the peak incidence of intussusception?
6-9 months
Where does intussusception normally occur?
Ileocaecal
What is a Meckel diverticulum?
Remnant of the vitello-intestinal duct, which can contain ectopic gastric, pancreatic or colonic tissue
What scan helps diagnose a Meckel diverticulum?
Technetium scan
How can a Meckel diverticulum present?
Intermittent painless PR bleed, intussusception, perforation
How does polyposis usually present?
Painless rectal bleeding
How is Peutz Jeghers syndrome inherited?
Autosomal dominant
What are the features of Peutz Jeghers syndrome?
Diffuse GI hamartomas
Hyperpigmentation of buccal mucosa and lips
Increased risk of malignancy
How are Gardener syndrome and familial adenomatous polyposis coli inherited?
Both autosomal dominant
What is the mutation in Gardener syndrome and familial adenomatous polyposis coli?
APC gene on 5q21
What are the features of Gardener syndrome?
Adenomatous polyposis plus bony lesions, subcutaneous tumours and cysts
What is the management for Gardener syndrome and familial adenomatous polyposis coli?
Endoscopic surveillance, usually prophylactic colectomy at end of 2nd decade
What does Grolin syndrome cause?
Hamartomas
What does Turcot syndrome cause?
Multiple colorectal adenomas with primary brain tumour
What is Hirschsprung disease?
Absence of ganglion cells in the myenteric plexus of the distal bowel
How common is Hirschsprung disease?
1:5000; males more than females
Where is the gene for Hirschsprung?
Chromosome 10
Which syndrome is Hirschsprung particularly associated with?
Down
What is the definitive test for Hirschsprung?
Rectal biopsy
How is Hirschsprung treated?
Surgical - excision of affected area
How is Shwachman-Diamond syndrome inherited?
Autosomal recessive
What are the features of Shwachman-Diamond syndrome?
Marrow failure Recurrent infections Increased risk of myelodysplasia and malignant transformation Short stature Skeletal anomalies
What are the features of Johanson-Blizzard syndrome?
Pancreatic insufficiency due to fatty replacement GI anomalies e.g. imperforate anus Deafness Unusual whorls of tissue in scalp Absent nasal cartilage Hypothyroidism
