What is the management approach for mast cell activation syndrome?

From the Guidelines

The management of mast cell activation syndrome (MCAS) involves a multi-faceted approach centered on symptom control and trigger avoidance, with first-line treatment typically including H1 antihistamines, H2 antihistamines, and mast cell stabilizers, as recommended by the most recent guidelines 1.

Key Components of Management

• First-line treatment: H1 antihistamines (such as cetirizine 10mg daily or loratadine 10mg daily), H2 antihistamines (like famotidine 20mg twice daily or ranitidine 150mg twice daily), and mast cell stabilizers (such as oral cromolyn sodium 200mg four times daily) 1
• Breakthrough symptoms: adding leukotriene modifiers like montelukast 10mg daily 1
• Severe reactions: injectable epinephrine (0.3mg for adults, 0.15mg for children), and patients should carry auto-injectors at all times 1
• Trigger avoidance: common triggers include certain foods, medications, temperature extremes, alcohol, stress, and physical exertion 1
• Nutritional support: vitamin C (500-1000mg daily) and vitamin D supplementation if deficient, and a low-histamine diet for those with gastrointestinal symptoms 1

Personalized Approach

• Treatment effectiveness varies among individuals, so therapy must be personalized through careful monitoring and adjustment 1
• Patients should maintain a detailed symptom diary to identify personal triggers 1
• In refractory cases, additional medications such as ketotifen, omalizumab, or low-dose aspirin might be considered under specialist supervision 1

Perioperative Management

• Multidisciplinary management is recommended with the involvement of surgical, anesthesia, and perioperative medical teams 1
• Pre-anesthetic treatment with anxiolytic agents, antihistamines, and possibly corticosteroids can help reduce the frequency and/or severity of mast cell activation events 1
• Certain perioperative drugs are considered safer, although the supporting data are anecdotal and not evidence-based 1

From the FDA Drug Label

CLINICAL STUDIES: Four randomized, controlled clinical trials were conducted with Cromolyn Sodium Oral Solution, Concentrate in patients with either cutaneous or systemic mastocytosis; INDICATIONS AND USAGE: Cromolyn Sodium Oral Solution, Concentrate is indicated in the management of patients with mastocytosis.

The management approach for mast cell activation syndrome (also referred to as mastocytosis) includes the use of cromolyn sodium.

• Cromolyn sodium has been associated with improvement in symptoms such as:
  • Diarrhea
  • Flushing
  • Headaches
  • Vomiting
  • Urticaria
  • Abdominal pain
  • Nausea
  • Itching Clinical improvement with cromolyn sodium can occur within 2-6 weeks of treatment initiation and may persist for 2-3 weeks after treatment withdrawal 2. Cromolyn sodium is indicated in the management of patients with mastocytosis 2.

From the Research

Management Approach for Mast Cell Activation Syndrome

The management approach for mast cell activation syndrome (MCAS) involves a combination of avoiding triggers, modulating mast cell activation, and managing symptoms.

• Avoiding triggers is crucial in managing MCAS, as identified by 3.
• Modulating mast cell activation can be achieved through various therapies, including over-the-counter medications, as noted in 3.
• Managing symptoms is also essential, and this can be done through the use of medications such as antihistamines, leukotriene receptor blockers, and corticosteroids, as discussed in 4.

Treatment Options

Treatment options for MCAS include:

• Continuous diphenhydramine infusion, which has been shown to improve anaphylactic reactions and decrease hospital readmissions, as reported in 5.
• Imatinib, which can provide benefits in KIT-D816V-negative mast cell disorders, as noted in 5.
• Blockade of mediator receptors, inhibition of mediator synthesis, and anti-IgE therapy, as discussed in 4.

Diagnostic Algorithm

A diagnostic algorithm has been proposed to help guide the investigation of patients with suspected MCAS, as outlined in 6.

• This algorithm aims to facilitate the management of patients with suspected MCAS by considering the principal diagnoses that may underlie MCAS, including severe allergy and systemic mastocytosis accompanied by severe mast cell activation.
• The algorithm also helps to exclude other conditions that may be misinterpreted as MCAS, as noted in 6.

Multidisciplinary Approach

A multidisciplinary approach is often necessary in managing MCAS, as patients may require investigations and treatments from various specialties, as discussed in 7.

• This approach can help to ensure that all underlying conditions and comorbidities are taken into account when establishing a management plan, as noted in 7.
• A personalized treatment approach is essential in providing optimal management and improving the quality of life for patients with MCAS, as emphasized in 7.