Mast Cell Activation Syndrome: Clinical Presentation and Management
Clinical Presentation
- Mast cell activation presents with episodic, multi-system symptoms affecting at least 2 organ systems, most commonly manifesting as cutaneous, gastrointestinal, cardiovascular, and neuropsychiatric symptoms 1, 2
- The American College of Allergy, Asthma, and Immunology recommends considering mast cell activation syndrome in patients with recurrent anaphylaxis or episodic multisystem symptoms 4
Dermatologic Manifestations
- Flushing of the face, neck, and chest is a common symptom of mast cell activation syndrome 1, 2
- Pruritus with or without rash is a frequent symptom, and the National Comprehensive Cancer Network recommends treating it with antihistamines 1, 2
Gastrointestinal Symptoms
- Diarrhea and abdominal cramping are common gastrointestinal symptoms of mast cell activation syndrome, and the Journal of the National Comprehensive Cancer Network recommends treating them with antihistamines and cromolyn sodium 1, 2
- Nausea and vomiting are also frequent symptoms, and the American College of Gastroenterology recommends considering mast cell activation syndrome in patients with recurrent gastrointestinal symptoms 1, 2
Cardiovascular Manifestations
- Anaphylaxis is the most severe presentation of mast cell activation syndrome, and the American Heart Association recommends immediate treatment with epinephrine 1, 2
- Light-headedness, presyncope, and syncope are common cardiovascular symptoms, and the National Comprehensive Cancer Network recommends treating them with antihistamines and fluids 1, 2
Treatment Algorithm
- The Journal of Allergy and Clinical Immunology recommends starting with combined H1 and H2 receptor antagonists at higher-than-standard doses for mast cell activation syndrome 3, 4
- The National Comprehensive Cancer Network recommends adding oral cromolyn sodium for persistent symptoms, particularly gastrointestinal manifestations 3
- Omalizumab is recommended for symptoms insufficiently controlled by conventional therapy, particularly recurrent anaphylaxis and severe skin symptoms 3, 6
Management of Osteopenia/Osteoporosis
- The National Comprehensive Cancer Network recommends initiating supplemental calcium and vitamin D with bisphosphonates for bone manifestations of mast cell activation syndrome 1, 2
- Denosumab is recommended as second-line therapy for patients with bone pain not responding to bisphosphonates 2
Acute Management of Anaphylaxis
- The American College of Allergy, Asthma, and Immunology recommends immediately assuming a supine position, administering intramuscular epinephrine, and calling emergency services for anaphylaxis or severe episodes 4, 5
- All patients with a history of systemic anaphylaxis or airway angioedema must be prescribed an epinephrine autoinjector with proper training 4