Question 21.1

A 16-year-old patient presents feeling generally lethargic after a recent episode of diarrhoea. Her blood results are as follows:


Patient Value

Adult Normal Range


78 g/L*

130 – 150

White Cell Count

14.5 x 109/L*

4.0 – 11.0

Platelet count

43 x 109/L*

150 – 300


17.1 mmol/L*

3.0 – 8.0


200 µmol/L*

60 – 120

a)    What is the most likely diagnosis?    (10% marks)

b)    List two pathogens that can cause this syndrome.    (10% marks)

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College answer

Not available.



This question being 20% of a 10-minute SAQ, you really don't have time to do anything other than react to the blood results at a subcortical level. Anaemia, meaning haemolysis? Thrombocytopenia, uremia, renal failure? Surely this is TTP/HUS, blurts your nucleus accumbens, as you move on to the next SAQ. Probably more on the HUS spectrum, as the college did not mention anything about fever or confusion, though the boundaries between TTP and HUS are not completely clear.

c) The list of possible organisms you could choose is actually rather large. From Karpman et al (2017):

  • Shigatoxin producers:
    • Enterohaemorrhagic Escherichia coli (EHEC)
    • Shigella dysenteriae
    • Citrobacter freundii
  • Streptococcus pneumoniae
  • Pseudomonas aeruginosa
  • Enteroviruses (Coxsackie A and B, Echovirus)
  • HIV
  • CMV


Fakhouri, Fadi, et al. "Haemolytic uraemic syndrome." The Lancet 390.10095 (2017): 681-696.

Karpman, Diana, et al. "Haemolytic uraemic syndrome." Journal of internal medicine 281.2 (2017): 123-148.