Table 4

Criteria for diagnosis of MCAS based on a consensus report by an international mastocytosis working group36 and the AAAAI mast cell disorder work group report37

ATypical signs of severe, recurrent (episodic) systemic MCA (often in form of anaphylaxis or crisis) (definition of systemic: involving at least two organ systems).
BObjective laboratory evidence of MC activation: preferred marker: increase in serum tryptase level (baseline to baseline plus 20%+2‚ÄČng/mL)
CResponse to therapy with MC-stabilising agents, drugs directed against MC mediator production or drugs blocking mediator release or effects
  • All three criteria need to be fulfilled for diagnosis of MCAS.

  • AAAAI, American Academy of Allergy, Asthma & Immunology; MC, mast cell; MCAS, mast cell activation syndrome.