Mast Cell Inhibitors for Mast Cell Activation Syndrome

Introduction to Mast Cell Stabilizers

The American Academy of Allergy, Asthma, and Immunology recommends cromolyn sodium as the primary mast cell stabilizer for mast cell activation syndrome, with a starting dose of 20-40 mg four times daily and gradual titration up to 200 mg four times daily over weeks 1, 2
The European Academy of Allergy and Clinical Immunology suggests that cromolyn sodium requires at least 1 month trial to assess efficacy, and is particularly effective for gastrointestinal symptoms and can help with cutaneous symptoms and cognitive function 1, 3, 4

The American College of Allergy, Asthma, and Immunology recommends second-generation non-sedating H1 antihistamines, such as fexofenadine and cetirizine, at 2-4 times FDA-approved doses, to reduce dermatologic manifestations and gastrointestinal symptoms 6, 7
The American Academy of Allergy, Asthma, and Immunology suggests that leukotriene modifiers, such as montelukast, are most effective when combined with H1 antihistamines, particularly if urinary LTE4 levels are elevated, to reduce bronchospasm and gastrointestinal symptoms 1, 7, 9

The National Institute of Allergy and Infectious Diseases recommends systemic steroids, such as prednisone, at 0.5 mg/kg/day, with slow taper over 1-3 months, for refractory cases of mast cell activation syndrome, but with caution due to potential adverse effects 1, 6, 7

The American Academy of Allergy, Asthma, and Immunology notes that aspirin may reduce flushing and hypotensive episodes associated with prostaglandin D2 secretion, but with caution due to potential triggering of mast cell activation in some patients 6, 7, 2
The European Academy of Allergy and Clinical Immunology suggests that anticholinergics, such as ipratropium bromide, may be effective for rhinorrhea, but have no effect on mast cell degranulation itself 9