Mast cell activation syndromes presenting as anaphylaxis

Area of Science:

• Immunology
• Allergy and Clinical Immunology
• Mast Cell Disorders

Background:

• Anaphylaxis is a severe systemic mast cell activation.
• Triggers include IgE-mediated, physical factors, clonal mast cell disease, or idiopathic causes.
• Mast cell activation disorders are classified as primary (clonal), secondary, and idiopathic.

Purpose of the Study:

• To discuss the diagnosis of Mast Cell Activation Syndrome (MCAS).
• To highlight MCAS in the differential diagnosis of recurrent anaphylaxis.
• To define MCAS criteria including mediator documentation and treatment response.

Main Methods:

• Review of literature on mast cell activation disorders.
• Clinical case analysis of patients with recurrent anaphylaxis.
• Diagnostic criteria for MCAS outlined.

Main Results:

• MCAS is a multisystem disorder.
• Objective documentation of elevated mast cell mediators is key.
• Favorable response to antimediator therapy supports MCAS diagnosis.

Conclusions:

• MCAS should be considered in patients with recurrent anaphylaxis of unknown cause.
• Diagnosis requires objective evidence of mast cell mediator release.
• Antimediator therapy response is a significant diagnostic indicator.