Mast Cell Activation Syndrome Management

Introduction to Treatment Approach

The American Academy of Allergy, Asthma, and Immunology recommends treatment based on specific mediator elevations, such as increased urinary LTE4 levels, which may be treated with leukotriene antagonists, and increased urinary PG metabolite levels, which may be treated with aspirin 1
Treatment efficacy should be assessed based on reduction in frequency and severity of symptoms, particularly focusing on morbidity and mortality outcomes, as recommended by the American Academy of Allergy, Asthma, and Immunology 1

Patients with clonal Mast Cell Activation Syndrome (MCAS) may progress to systemic mastocytosis, requiring monitoring, as recommended by the American Academy of Allergy, Asthma, and Immunology 1
A multidisciplinary approach involving surgical, anesthesia, and perioperative teams is recommended for patients undergoing anesthesia, according to the National Comprehensive Cancer Network 2

Safer anesthetic options include induction with Propofol, inhalational anesthesia with Sevoflurane or isoflurane, analgesics such as Fentanyl or remifentanil, and local anesthetics like Lidocaine and bupivacaine, while avoiding muscle relaxants atracurium and mivacurium, and succinylcholine 2
Exercise caution with opiates such as codeine and morphine, but do not withhold if needed for pain management, according to the National Comprehensive Cancer Network 2
High-risk obstetric patients with mast cell activation syndrome require a multidisciplinary team, including high-risk obstetrics, anesthesia, and allergy, with a focus on symptom alleviation with medications that minimize fetal harm, according to the National Comprehensive Cancer Network 2

First-line treatment for Mast Cell Activation Syndrome (MCAS) includes H1 and H2 antihistamines, with nonsedating H1 antihistamines being generally preferred, targeting symptoms such as dermatologic manifestations, tachycardia, and abdominal discomfort, as recommended by the American Academy of Allergy, Asthma, and Immunology 1
Additional treatments for MCAS include:

First-generation H1 antihistamines can cause cognitive decline, particularly in elderly patients, and should be used with caution, as reported by the American Academy of Allergy, Asthma, and Immunology 1
Aspirin introduction should be done in a controlled clinical setting due to the risk of triggering mast cell degranulation, according to the American Academy of Allergy, Asthma, and Immunology 1
Patients should be counseled that the onset of action of cromolyn sodium can be delayed and should take it for at least 1 month before deciding whether it is helping, according to the American Academy of Allergy, Asthma, and Immunology 1
Eliminating additives in drugs by compounding is not recommended based on evidence, as reported by the American Academy of Allergy, Asthma, and Immunology 1

For patients with osteopenia or osteoporosis, supplemental calcium and vitamin D, bisphosphonates, and consideration of anti-RANKL monoclonal antibody (e.g., denosumab) as second-line therapy for refractory bone pain are recommended, according to the National Comprehensive Cancer Network 2

In anaphylaxis events, check serum tryptase level within 30–120 minutes of symptom onset, according to the National Comprehensive Cancer Network 2