Common DDx

Question 1

What are your differentials for this person’s low mood?

How would you evaluate?

Answer 1

DDx:

• Hypothyroid
• Anaemia
• Nutritional deficiency
• Renal failure

Question 2

How would you investigate this person’s weight loss?

Answer 2

Normal appetite

• catabolic state
• malabsorption issues
• Endo -> DM / hyperthyroid

Decreased appetite

• psychiatric
• medical (malignancy, organ failures, chronic infection, chronic inflammation)
• drugs

Question 3

How would you investigate this person’s SOB?

Answer 3

a

Question 4

How would you investigate this person’s recurrent CP?

Answer 4

DDx:

• Cardiac -> IHD, pericarditis, aortic stenosis
• Resp -> PTx, infection, PE, COPD/asthma, cancer
• GIT -> GORD
• MSK -> costochondritis
• Psych -> anxiety
• Anaemia

Ix:

• Examination
• ECG
• Bloods: troponin, FBE, D-Dimer
• CXR
• CTPA
• Cardiac stress testing
• Consider echo

Question 5

How would you investigate this person’s diarrhoea?

Answer 5

DDx:

• Infection
• Inflammatory
• Malabsorption
• Malignancy

Infective
○ Stool MCS + OCP
○ C.diff toxin if relevant, can check AXR for toxic megacolon

Malabsorptive
	○ Faecal elastase 
	○ Coeliac serology 
	○ Fat soluble vitamins / iron 
	○ TFT

Inflammatory
○ Faecal calprotectin (high)
○ CRP / ESR

Malignant
○ CT
○ C’scope + biopsy

Question 6

How would you investigate this person’s fatigue?

Answer 6

a

Question 7

How would you investigate this person’s dizziness?

Answer 7

Neuro:

• Vertigo
• > central
• > peripheral

Cardiac:

• Postural hypotension
• arrhythmia
• valvular

Severe deconditioning

Question 8

How would you investigate this person’s foot drop?

Answer 8

a

Question 9

What are your differentials for ascites?

Answer 9

Liver -> portal hypertension
Cardiac -> RHF
Renal -> nephrotic syndrome 
Malignancy 
Infection -> TB

I would differentiate these based on ascitic fluid results, with cell count / cytology / culture
Serum to ascites albumin ratio will also determine if portal HTN is present (>11)

Question 10

How will you evaluate this person’s peripheral neuropathy?

Answer 10

DDX

• Toxic -> Drugs, ETOH
• Metabolic -> DM, TFT, B12, uraemia, paraprotein
• Autoimmune -> CIDP, CTD, HIV
• Compressive -> radiculopathy

EMG / NCS -> determine axonal (reduced amplitude) / demyelinating (slow velocity) / myopathy
Consider spinal imaging
Consider LP in demyelinating pattern

Question 11

How would you evaluate this person’s headache?

Answer 11

Tension
Migraines 
SOL 
IIH
Autonomic encephalgias
Cerebral sinus thrombosis

Question 12

How would you evaluate this myopathy?

Answer 12

DDx:
CTD -> autoimmune myositis
Toxins -> ETOH, steroids
Endocrine -> thyroid, cortisol
Malignant -> paraneoplastic

Ix:
CK
EMG
Muscle biopsy

Question 13

How would you investigate this person’s weight loss?

Answer 13

Appetite increased?

• thyroid
• DM
• malabsorption

Decreased appetite?

• malignancy
• chronic inflammatory state / organ failure
• chronic infection
• psychiatric illness

Question 14

How would you Ix Nausea?

Answer 14

Meds
GI
-> inflam
-> infection
-> GORD
-> malignancy
CNS
Mood
Metabolic