Mock exam errors Flashcards
Diagnosis:
A 65 year old obese man presents with gradual worsening dysphagia for solids, which had initially been intermittent. He has had GORD for many years but is poorly compliant with medication.
Benign oesophageal stricture
Healing of oesophageal damage inflicted in GORD involves the deposition of collagen. This causes contraction of the distal oesophagus which causes the formation of strictures. This is often associated with dysphagia for solids. Other complications of GORD include oesophageal ulcer, haemorrhage or perforation, Barrett’s oesophagus and oesophageal adenocarcinoma.
Diagnosis:
A 30 year old woman presents with aspiration pnuemonia. She has a long history of intermittent mild dysphagia for both liquids & solids and often suffers from severe retrosternal chest pain. Occasionally she gets food stuck but overcomes this by drinking vast amounts of water.
Achalasia
This is achalasia which is a motility disorder with loss of peristalsis in the distal oesophagus and failure of the LOS to relax in response to swallowing. This presents commonly with dysphagia to both liquids and solids, regurgitation and retrosternal chest pain, which can be slowly progressive over time. In structural obstruction such as cancer, dysphagia to liquids is uncommon unless the disease is very advanced. Retrosternal pressure experienced can be precipitated by drinking liquids but is eased by continuing to drink, and the pain may be relieved by cold water. This may wake the individual from sleep. A UGI endoscopy is needed to exclude malignancy as a cause of dysphagia. The diagnosis is established on manometry or barium studies. Treatment is symptomatic.
Diagnosis:
A male child is found to have moderate learning difficulties and behavioural problems. There is a family history of learning difficulties. On examination he has large testicles, epicanthic folds and large ears. DNA testing reveals trinucleotide repeat expansion (CGG).
Fragile X syndrome
This is fragile X syndrome. History includes learning difficulties, which can range from mild to severe, social communication difficulties (patients may be autistic), hyperactivity and attention deficit and motor co-ordination difficulties. There may be a FH of learning difficulties too. Examination may reveal macrocephaly, low muscle tone, long face, high arched palate, prominent jaw, big testicles (macro-orchidism), large ears and strabismus. DNA testing is diagnostic and reveals a ragile site on Xp27.3 (FRM1 gene position). This is characterised by trinucleotide repeat expansion (CGG) to more than 200 copies.
Causative agent:
A 31 year old woman is brought into A&E by her boyfriend who claimed she may have had too many ‘sleeping pills’ after he tried to break up with her. Prior to this she had drank two bottles of wine and consumed three chocolate cakes. She is ataxic with slurred speech with a GCS of 10. Her medical file shows she is taking medication for panic attacks.
Benzodiazepines
This woman here who is clearly distraught after her breakup has overdosed on benzodiazepines. The clue here is given when it says she is taking medication for panic attacks at the moment. BZDs are the most commonly prescribedmedication for anxiety disorders, sedation and sleep. Patients may present like this and may be intentional or accidental in nature, and may be in combination with other CNS depressants such as alcohol and opioids in older people. Occasionally overdose is due to medication error. The key feature of overdose is excessive sedation and anterograde amnesia. Vital signs are unremarkable. Larger doses can lead to coma and respiratory depression. Treatment is symptomatic and may include assisted ventilation and haemodynamic support and death is uncommon and often due to mixed overdoses with other depressants such as alcohol. Flumazenil is a BZD antagonist that can be used in first time or infrequent users to reverse CNS depression but it is contraindicated in those who are long-term of frequent users (like this patient) due to the risk of provoking seizures, which outweights the benefits.
Causative agent:
A 29 year old man presents to A&E with agitation, tremor, dilated pupils, tachycardia, arrhythmias, convulsions after ingesting an overdose of an unknown substance.
Sympathomimetics
The symptoms described here are those of sympathetic activation and the overdose here is of sympathomimetics. This group of drugs mimic the effects of transmitter substances of the sympathetic nervous system such as adrenaline, dopamine and noradrenaline.
Diagnosis:
A 76 year old woman admitted with a chest infection develops non-bloody diarrhoea on the ward. She was on cefuroxime and erythromycin for her chest. She appears unwell and there is a fever. CRP is elevated.
Clostridium difficile
This is infection with clostridium difficile with the major risk factor here of antibiotic exposure due to the recent chest infection. The most common ones implicated are ampicillin, second and third generation cephalosporins, clindamycin and fluoroquinolones, especially if used in the preceding 3 months (though most manifestations occur on days 4 through to 9 of antibiotic therapy). Diarrhoea may range from a few loose stools to severe diarrhoea, though absence could be related to toxic megacolon to paralytic ileus. Abdominal pain is also common as is fever. C. difficile produces 2 exotoxins which are responsible for its pathogenicity. These are called toxin A and toxin B (A is thought to be more important than B) which lead to an inflammatory response in the large bowel, increased vascular permeability and the formation of pseudomembranes. Colonic pseudomembranes look like raised yellow and white plaques against an inflamed mucosa and are composed of neutrophils, fibrin, mucin and cellular debris. The diagnostic standard is with cytotoxic tissue culture assay. Treatment involves discontinuing the implicated antibiotic and beginning oral metronidazole or vancomycin. 5-20% will have a recurrence on discontinuing treatment and will need a second course.
Diagnosis:
A 30 year old female presents with a 3 month history of bloody diarrhoea and vague lower abdominal cramps. She gave up smoking a few months ago. The doctor feels that this could have contributed to her condition.
Ulcerative colitis
While this could be Crohn’s disease, bloody diarrhoea is more commonly a presentation of UC than Crohn’s. UC is characterised by diffuse mucosal inflammation running a relapsing and remitting course. Bloody diarrhoea is commonly experienced by patients who may also complain of other symptoms such as (lower) abdominal pain, faecal urgency and the host of extra-intestinal manifestations associated with UC. These include erythema nodosum, pyoderma gangrenosum, sacroiliitis, ankylosing spondylitis, PSC, aphthous ulcers, episcleritis, peripheral arthropathy and anterior uveitis. Another clue in this question which makes you pick UC instead of Crohn’s is the fact the patient has given up smoking. While I remain convinced this link as a risk factor is a weak one, you should try to think like an EMQ when answering EMQs (generally the information is there for a reason). There is a weak risk of UC development in non-smokers and those who were a former smoker (though it is an established link). This is based on a review paper published by some German medics in an exciting journal named ‘Inflammatory Bowel Diseases’. Should be you interested you can check it out: Inflammatory Bowel Diseases. 10(6):848-859, November 2004 (just read the abstract if you want)
Diagnosis of UC requires endoscopy with biopsy and a negative stool culture to rule out infectious gastroenteritis. Flare ups are usually linked to pathogens so a stool culture will always be needed in these cases. Toxic megacolon is a complication which is associated with a risk of perforation. UC is also linked with bowel adenocarinoma and PSC. Treatment involves mesalazine (5-ASA) used to induce and maintain remission.
Diagnosis:
A 25 year old Jewish man presents to A&E with some abdominal discomfort, weight loss with associated loss of appetite. His history revealed loose and bloody stools. Examination reveals tenderness in the RLQ. He is booked in for endoscopy.
Crohn’s disease
This patient gives a history of IBD. This could well be UC where the mainstay of treatment is with 5-ASA. A colonoscopy is required to assess the extent of disease and for a definitive diagnosis. Biopsy in CD will show transmural granulomatous inflammation. CD can affect the whole GIT but favours the TI (RLQ pain) and proximal colon and is macroscopically characterised by skip lesions. UC on the other hand is characterised by the presence of crypt abscesses, which is pathognomic. CD risk is increased 3-4 fold by smoking whereas smoking seems protective in UC. The mainstay of treatment in CD is with steroids and azathioprine to revent relapses and for those suffering side effects of steroid treatment. TNF-alpha inhibitors also have a role. Surgery in CD is only indicated in a small number of patients who bleed, for bowel perforation and cases of complete obstruction. The aim is to rest distal disease by temporarily diverting faecal flow.
Diagnosis:
A 60 year old patient presents with SOB and haemoptysis. O/E the patient is tachycardic, tachypnoeic with swollen ankles and bilateral basal crepitations
Left ventricular failure
LVF causes congestion in the pulmonary circulation so the symptoms are respiratory with evidence here of pulmonary oedema. As seen in this patient, there is SOB and there may also be orthopnoea. This is why you can ask patients in a cardiac history how many pillows they sleep with. PND can also occur as well as ‘cardiac asthma’. RVF leads to a backlog of blood and congestion of the systemic capillaries. This causes peripheral oedema and ascites and hepatomegaly may develop. Nocturia may be a symptom as fluid returns from the legs when the patient lies down flat. This patient does have peripheral oedema too so technically has CCF (congestive cardiac failure), but the best option on the list is LVF.
Diagnosis:
A 69 year old lady presents with a sudden onset of fever and coughing up a purulent, rusty coloured sputum. Examination of her chest showed signs of consolidation.
Streptococcus pneumoniae
The rusty coloured sputum is hinting at a pneumococcal pneumonia.The patient has presented with common symptoms of fever and a productive cough. Examination findings are also consistent – have a think about what would actually be found while performing a respiratory examination on this patient. There may also be SOB, chills, rigors and pleuritic chest pain. The most specific and sensitive test is a CXR (PA and lateral) and initial treatment of a CAP is empirical with antibiotics. Often diagnosis is made solely on history and examination findings. Management is guided by the patient’s CURB-65 score.
Diagnosis:
A 21 year old male has a 3 day history of hoarseness. He has pain in his throat which is worse on talking and eating. O/E his throat appears normal.
Laryngitis
Laryngitis, as the name would suggest, is inflammation of the larynx, which can lead to oedema of the true vocal folds. It has both infectious and noninfectious causes such as vocal strain. Symptoms of acute disease are most commonly hoarseness, generally over a period of less than a week, usually preceded by viral URTI and usually self limiting. The pain on swallowing and sore throat is common of URTIs. An exudate or cervical lymphadenitis would suggest bacterial infection instead. Treatment begins, as always, with ABC and airway assessment. Chronic laryngitis presents with hoarseness lasting more than 3 weeks and this needs investigating due to the fact that symptoms may be similar to cancer of larynx. Antibiotics are given in bacterial cases or otherwise voice rest and hydration is sufficient.
Ix:
A 43 year old man with a long history of excess alcohol consumption presents with haematemesis. O/E his is clubbed and has spider naevi.
Abdominal ultra sound scan (USS)
This is hepatic cirrhosis leading to clubbing. The haematemesis is secondary to oesophageal varices and he has signs of chronic liver disease. LFTs are non-specific however ultrasound can show signs of advanced cirrhosis. There may be liver surface nodularity (remember cirrhosis entails nodular regeneration), small liver and possible left/caudate lobe hypertrophy. Signs of portal hypertension may also be picked up such as ascites, splenomegaly and increased diameter of the hepatic portal vein. The most specific and sensitive test is a liver biopsy, which is not given as an option here. Additionally abdominal CT or MRI can also be done similar to USS, with similar findings.
Ix:
A 50 year old woman has developed weight loss and passes loose pale stools. She has mouth ulcers and is anaemic. She is taking thyroxine for myxoedema.
Endomysial antibodies
This is a common condition in the US and Europe. Coeliac disease most commonly presents with IDA, although it can also lead to a macrocytic anaemia with mainly folate deficiency (though B12 is also affected but hepatic stores last several years). The mouth ulcers are a sign of this. There are also GI symptoms resulting from malabsorption. It is an autoimmune condition (the presence of another autoimmune condition here is a risk factor) triggered by gluten peptides found in wheat, rye and barley. The ultimate best test is duodenal biopsy and histology to show intra-epithelial lymphocytes, villous atrophy and crypt hyperplasia. Macroscopic changes may be present but endoscopy is generally unhelpful. The test of choice before performing such an invasive confirmatory test is to look for elevated anti-gliadin antibodies. Anti-tissue transglutaminase is less accurate and endomysial antibody is more expensive and has lower sensitivity, though is the only option on this list specific for coeliac.
It is worth knowing about the Schilling test as it is frequently examined. However, it is no longer routinely done in clinical practice. In this test, IM vitamin B12 is given to saturate stores. Then oral radiolabelled B12 is given and urine is collected over 24 hours. The amount excreted is lower in B12 malabsorption. If this is not corrected by IF the problem is with the ileum and not inadequate IF.
Ix:
A 10 year old girl with a history of recurrent chest infections has developed pale floating stools and weight loss.
Sweat test
CF is autosomal recessive and the mean age of death is around 40. There is currently no cure for this condition. The reccurent chest infections and greasy stools (fat malabsorption due to pancreatic insufficiency) should make you think of CF. A persistent cough which is productive would also raise suspicions. Additionally, you may find nasal polyps and hepatomegaly and/or splenomegaly and a congenital absence of the vas deferens in males. There may also be failure to thrive in infants. The most conclusive diagnostic test is the sweat test which is positive if sweat chloride is >60mmol/L. Serum IRT from a heel prict blood spot allows screening of newborns. CF is a genetic condition with abnormal salt and water transport due to mutations in the CFTR (an apical anion channel). Heterozygotes generally do not demonstrate disease.
Ix:
A 45 year old man has recurrent epigastric pain, weight loss and steatorrhoea. He has a previous history of alcoholism.
ERCP
This is chronic pancreatitis which is most commonly associated with chronic alcohol abuse. Features include the epigastric pain here, which classically radiates to the back, and steatorrhoea from malabsorption (pale, foul-smelling and difficult to flush stools). There may additionally be DM due to pancreatic failure and the patient may be malnourished. The diagnosis is based on findings and imaging – your options are USS which is less sensitive, or CT, which is more sensitive but involves radiation exposure. AXR is not a sensitive enough test. However, this question is looking for the best test which is ERCP, commonly considered the most accurate test with high sensitivity and specificity. It is limited in use though due to cost and the risk to the patient. Characteristically ERCP would show beading of the main pancreatic duct as well as irregularities in the side branches. Faecal elastase-1 is inaccurate for diagnosing mild to moderate pancreatic insufficiency, and anyway has unacceptably low sensitivity.
There is no real definitive treatment, which is mainly symptomatic and the underlying and precipitating factors are treated – in this case, this man’s alcohol excess. Complications of chronic pancreatic imflammation include the development of pseudocysts, calficiation, DM and malabsorption.
Diagnosis:
A 6 year old presents with mild jaundice and some pain and swelling of his fingers. O/E you note splenomegaly.
Haemolytic anaemia
Africans have higher incidence of sickle cell anaemia. This is a presentation of bone pain here with dactylitis, consistent with hand-foot syndrome which can be what young infants and children present with (it is often a child’s first presentation of disease). The jaundice here is due to haemolysis and so while this is sickle cell anaemia, the options are trying to get you to think a bit about the best fit here which would be haemolytic anaemia. About 8% of black people carry the gene and the prevalence is high in sub-Saharan Africa. The condition is autosomal recessive and therefore occurs in 1 in 4 pregnancies where both parents carry the sickle gene. Sickling occurs when RBCs containing HbS become distorted into a crescent shape. Patients with sickle cell anaemia have no HbA at all. If both parents carry the sickle cell gene, there is a 1 in 4 chance of giving birth to a child with sickle cell anaemia. Sickle cell disease also includes other conditions such as HbS from one parent with another abnormal Hb or beta thalassaemia from the other parent such as HbS-Beta thal and HbSC. Treatment goals here include fluid replacement therapy, pain management and symptomatic control.
Diagnosis:
On liver biopsy a moderate chronic inflammation is observed. Special stains identify antigens from a double stranded DNA virus within the cytoplasm of hepatocytes.
Hepatitis B
Hepatitis B is a DNA virus which is transmitted percutaneously and permucosally. It is also a STI. HCV is an RNA virus and RNA-PCR will be positive. A brief bit about hepatitis B markers: HBsAb appears several weeks after HBsAg disappears and in most patients suggests a resolved infection and life-long immunity (it is also detectable and titres are measured in those immunised with the HBV vaccine). HBsAg on the other hand appears 2-10 weeks after exposure to HBV and usually, in self-limiting acute cases, becomes undetectable after 4-6 months of infection. Persistence for >6 months implies chronic infection. Core antibody (IgM) appears within weeks of acute infection and remains detectable for 4-8 months and can be the only way to diagnose acute infection during the period when surface antigen disappears but before surface antibody has appeared. Chronic infection is indicated by IgG core antibody. The best single test to screen household contacts of infected individuals to determine the need to vaccinate is still HBcAb. E antigen is a soluble viral protein in serum which is part of the early acute infection and disappears soon after peak ALT levels. Presence >3 months indicates chronic infection is likely. E antigen being present in those with surface antigen indicates greater infectivity and a high level of viral activity and replication.
Mgx:
A 40 year old woman with a history of hypertension was brought in to casualty two hours ago having taken a whole bottle of her medication in an attempt to commit suicide. She suddenly collapses with a pulse of 30bpm and a BP of 70/30.
IV-glucagon
Glucagon stimulates adenyl cyclase which acts to increase intracellular cAMP and to therefore increase cytosolic calcium and cardiac contractility. Hypotension and bradyarrhythmias are the most common initial findings of beta blocker toxicity. If IV glucogon is not available then high-dose insulin can be used instead with co-administration of dextrose to maintain blood glucose levels.
Mgx:
A 45 year old homeless man complains of headache, abdominal pain, nausea and dizziness. He admits to having drunk anti-freeze on the previous night. He is hyperventilating and slightly drowsy.
IV-ethanol
Antifreeze is ethylene glycol. It is a sweet-tasting, odourless and colourless liquid and the substance itself is non-toxic and initially causes inebriation. Toxicity appears within 12-24 hours and is due to metabolic acidosis and the formation of calcium oxalate from one of the metabolites. Oxalate deposits in the lungs, myocardium and kidneys leading to organ damage and renal failure, and hypocalcaemia may also occur due to the consumption of circulating calcium. Ethylene glycol is not absorbed by activated charcoal and gastric decontamination is pointless regardless of time since consumption. The first line treatment is fomepizole (4-methylpyrazole) which is a competitive inhibitor of alcohol dehydrogenase, an enzyme involved in catalysing the initial steps in metabolism of ethylene glycol and methanol into toxic metabolites. However, this is not on the list, and oral ethanol (loading dose or infusion) can be used in this case (have a think about why ethanol would work as an antidote, if you think back to how ethanol is metabolised). Dialysis may well be required.
Ix:
A 45 year old man presents with sudden onset epigastric pain, constant in nature. He has had several previous episodes. He drinks half a bottle of whisky per day.
Acute pancreatitis
This patient has acute pancreatitis – the cause here being alcohol. He is describing mid-epigastric pain. This pain classically radiates around to the back, which in itself is almost diagnostic. Complicated haemorrhagic pancreatitis may exhibit Cullen’s sign, Grey-Turner’s sign and Fox’s sign. Make sure you know what these are and you are familiar with the causes of acute pancreatitis (GET SMASHED). Those caused by hypocalcaemia may also display Chvostek’s sign and Trousseau’s sign.
Mgx:
A 50 year old male collapses in hospital while you are taking a history from the patient next to him. After 10 seconds, he is rapidly jerking his head with tonic stiffening arms quickly followed by clonic jerking. He becomes incontinent of urine and unresponsive.
IV lorazepam
This is a tonic-clonic, generalised seizure. It is characterised by LOC and widespread motor tonic contractions followed by clonic jerking movements. There will characteristically be a suppressed level of arousal following the event. This may either reflect a primary generalised episode or a focal seizure with secondary generalisation. The main aim of acute treatment is to terminate the seizure and to protect the airway. Management always starts with basic life-support (like every acute emergency) and your ABCs. IV access needs to be established (bloods sent to the lab too and serum glucose measured to test for reversable causes of seizure activity – thiamine should also be given to the patient if there is any concern about deficiency and hypoglycaemia, for instance in alcohol abuse). The following are needed: ECG, pulse oximetry, ABG. IV lorazepam is the preferred initial therapy, though rectal diazepam can be used if there is no IV access. If BZDs fail to stop the seizure then phenytoin or fosphenytoin can be tried.
After the episode, MRI and EEG are essential in diagnosing an epilepsy syndrome. During the episode of generalised tonic-clonic activity, the EEG will show bilateral synchrony in the epileptiform activity. If this is a one-off seizure in which a provoking factor, such as electrolyte disturbance or hypoglycaemia, has been identified then there is no need for therapy for epilepsy. In unprovoked cases, this depends on history, examination, EEG and MRI. Treatment may not be needed the first time but after a second unprovoked instance, therapy is generally recommended.
Mode of inheritance:
Duchenne muscular dystrophy
X-linked recessive