The disease is potentially serious. In the event of a legitimate suspicion, admission to a pediatric or medical department in hospitals with the option of intensive care is recommended.

Examples of disease signs that require treatment (from UpToDate 2013):

• Patient with CNS symptoms, cytopenias, coagulopathy and ferritin above 3000 ng / mL or rapidly increasing ferritin or increased sCD25 (soluble IL-2 receptor)
• Patient with hypotension, fever, without response to broad spectrum antibiotics and ferritin over 3000 ng / mL or rapidly increasing ferritin or increased sCD25

1. Methylprednisolone IV in 3 consecutive days
   • High dose corticosteroids are adequate treatment in excess of 50%
2. If CNS affection is dexamethasone relevant (the drug crosses the blood-brain barrier)
3. Fresh frozen plasma if low fibrinogen and threatening bleeding
4. Sepons all antirevulsive medication other than corticosteroids / prednisolone 4mg / kg / d / dexamethasone 6mg / m2 / day
5. Cyclospirine-A 2 - 5mg / kg / day can be used
6. Intravenous immunoglobulin (IVIG) can be considered
7. Etoposide (Etopophos) is a cytostatics used abroad. Not registered in Norway
8. Cyclofosfamine (Sendoxan) is an alternative
9. Transition to methotrexate for maintenance therapy if needed
10. Transfusion if hemoglobin falls (and not contraindications) or if platelets lower than 50.000

Interlevkin-1 inhibitors (Kineret) also have an effect in some cases.

HLH-2004 protocol

For children with MAS / HLH, one can follow HLH-2004 protocol based on a study that has been ongoing since 2004-2017.

Follow-up

• Take daily blood tests initially
• Follow clinical signs (temperature, rash, lymphadenopathy, hepatosplenomegaly, neurological symptoms)
• Bloodcell counts
• Coagulation: INR, fibrinogen, D-dimer
• Ferritin, renal function, electrolytes
• Liver enzymes

Macrophage activation syndrome, BINDEVEVSSYKDOMMER.no

Recommended Literature: Rosee PL, 2019 (adults)