Macrophage Activation Syndrome in children with rheumatic disease

exp date isn't null, but text field is

ALERT!

Macrophage Activation Syndrome (MAS) is a rare but life-threatening condition that can affect children with rheumatic disease, particularly those with Systemic Onset Juvenile Idiopathic Arthritis.

MAS should be considered in at risk children presenting with fever +/- rash: for rapid deterioration with coagulopathy, liver dysfunction, pancytopenia shock and encephalopathy may evolve. If you suspect MAS, the following tests should be sent as urgent:

FBC
Coagulation
ESR
Ferritin*

UE
LFT
CRP
LDH
Triglycerides

Monitor BP
Monitor urine output
Monitor TPR

* ensure the ferritin is processed as urgent, discussion with laboratory staff is advised.

These tests are available by a TRAK order set:  MAS

Biochemical features of MAS include:

  • ferritin >500
  • falling Hb, Wcc or platelets
  • a low or falling ESR (often out of context with CRP)
  • low fibrinogen,
  • elevated LDH,
  • elevated triglycerides

Blood test abnormalities should be discussed promptly with the on-call paediatric consultant or paediatric rheumatologist.

Early recognition and prompt treatment of this condition is vital.

 

Editorial Information

Last reviewed: 18 May 2016

Next review: 18 May 2018