What is the treatment for mastocytosis?

Treatment of Mastocytosis

The primary treatment for mastocytosis focuses on suppressing mast cell mediator-related symptoms through a combination of H1 and H2 antihistamines, mast cell stabilizers like cromolyn sodium, and avoidance of triggering factors, with cytoreductive therapy reserved only for aggressive variants with life-threatening manifestations. 1

Classification and Treatment Approach

Mastocytosis treatment varies based on disease classification:

Cutaneous Mastocytosis (Common in Children)

• First-line therapy: H1 antihistamines for pruritus, flushing, urticaria, and tachycardia 1
  • Options include diphenhydramine, hydroxyzine, and cetirizine
• For gastrointestinal symptoms:
  • H2 antihistamines (ranitidine, famotidine) for gastric hypersecretion 1, 2
  • Oral cromolyn sodium for diarrhea, abdominal pain, nausea, and vomiting 1, 3
• For refractory symptoms: Combined H1 and H2 antihistamines 1

Systemic Mastocytosis

• Indolent forms: Anti-mediator therapy similar to cutaneous mastocytosis 1
• Advanced forms (Aggressive SM, SM with associated hematologic neoplasm, Mast Cell Leukemia):
  • Cytoreductive therapy is recommended due to organ damage and shortened survival 1
  • Clinical trials with selective KIT D816 inhibitors should be considered 1

Specific Medications and Their Uses

Anti-mediator Therapy

1. H1 Antihistamines 1

   • Control skin symptoms (pruritus, flushing, urticaria)
   • Manage neurologic symptoms (headache, poor concentration)
   • Address cardiovascular symptoms (presyncope, tachycardia)

2. H2 Antihistamines 1, 2

   • Indicated for pathological hypersecretory conditions in mastocytosis
   • Manage gastric symptoms and prevent peptic ulcer disease

3. Cromolyn Sodium 1, 3

   • FDA-approved for mastocytosis
   • Effective for diarrhea, flushing, headaches, abdominal pain, and itching
   • Available as oral solution and topical preparations for cutaneous symptoms

4. Emergency Medications

   • Epinephrine for acute mast cell activation attacks with hypotension, wheezing, or laryngeal edema 1
   • All patients should carry two auto-injectors of epinephrine 1

Avoidance of Triggering Factors

Triggers that should be avoided include 1:

• Temperature extremes (especially hot temperatures)
• Anxiety and stress
• Physical stimuli that can cause mechanical irritation
• Certain medications that can trigger mast cell degranulation

Special Considerations

For Procedures and Surgery

• Premedications are recommended before invasive procedures 1
• Communication with healthcare providers about the diagnosis is essential to prevent life-threatening episodes 1

For Severe or Refractory Cases

• Leukotriene receptor antagonists for skin and gastrointestinal symptoms not responding to other therapies 1
• Aspirin for symptoms associated with elevated prostaglandin levels (use with caution as it may trigger mast cell activation) 1
• Omalizumab for insufficiently controlled symptoms 1
• Cytoreductive therapy only for life-threatening aggressive variants 1

Monitoring and Follow-up

• Follow-up every 6-12 months for cutaneous mastocytosis 1
• Monitor serum tryptase levels, with values >20 μg/L indicating increased mast cell burden 1
• Assessment of symptoms using standardized tools is recommended for indolent and smoldering systemic mastocytosis 1

Prognosis

• Most pediatric cases of cutaneous mastocytosis have a favorable outcome with spontaneous regression 1
• Systemic mastocytosis prognosis depends on the subtype, with advanced forms having decreased life expectancy 4

Remember that while most forms of mastocytosis follow a benign course, education about the disease and proper management of symptoms are crucial for improving quality of life and preventing severe reactions 1, 5.