Haematology mnemonic

Clinical pentad of thrombotic thrombocytopenic purpura

The mnemonic

FAT RN

What each word stands for

  • FFever
  • AAnaemia (microangiopathic haemolytic)
  • TThrombocytopenia
  • RRenal dysfunction
  • NNeurological signs

Why it matters clinically

Prompts urgent plasma exchange when TTP is suspected, caused by ADAMTS13 deficiency.

Where it stops being reliable

The full pentad is present in only a minority of patients, so do not wait for all five.

Teaching aid, still awaiting independent review. Confirm facts in a standard source.

More mnemonics

Common questions

What is the Haematology mnemonic?

FAT RN. It helps you recall: Clinical pentad of thrombotic thrombocytopenic purpura.

What does "F" stand for?

Fever

What does "A" stand for?

Anaemia (microangiopathic haemolytic)

What does "T" stand for?

Thrombocytopenia

What are all the parts of the FAT RN mnemonic?

F: Fever; A: Anaemia (microangiopathic haemolytic); T: Thrombocytopenia; R: Renal dysfunction; N: Neurological signs.

Which topic does this mnemonic belong to?

It belongs to Haematology in Pathology.

Where does this mnemonic stop being reliable?

The full pentad is present in only a minority of patients, so do not wait for all five.

How is this useful clinically?

Prompts urgent plasma exchange when TTP is suspected, caused by ADAMTS13 deficiency.

How do I make this mnemonic stick?

Say it aloud, write it from memory tomorrow, then again in a week. Then test yourself on a Pathology question about Haematology.

Is this a standard mnemonic?

It is a teaching aid written or adapted by our team. Some resemble ones students share informally. Check any fact that matters in a standard source.