What is the treatment for mastocytosis?

Treatment of Mastocytosis

The primary treatment for mastocytosis involves a combination of trigger avoidance, H1 and H2 antihistamines, and mast cell stabilizers to control symptoms and improve quality of life. 1

Treatment Algorithm

Step 1: Trigger Avoidance

• Avoid known triggers that cause mast cell degranulation:
  • Control temperature exposure (both hot and cold extremes)
  • Manage stress and anxiety
  • Avoid physical triggers (friction, pressure on skin lesions)
  • Avoid medications that can trigger mast cell activation (NSAIDs, opioids, alcohol)

Step 2: Pharmacologic Treatment for Symptom Control

First-line medications:

• H1 antihistamines: Effective for controlling pruritus, flushing, urticaria, and tachycardia 1

  • Options include diphenhydramine, hydroxyzine, and cetirizine
  • Both sedating and non-sedating antihistamines may be used

• H2 antihistamines: Help control gastric hypersecretion and peptic ulcer disease 1

  • Options include ranitidine or famotidine

• Mast cell stabilizers: Oral cromolyn sodium is FDA-approved for mastocytosis 2

  • Particularly effective for gastrointestinal symptoms (diarrhea, abdominal pain, nausea, vomiting) 2
  • Clinical improvement typically occurs within 2-6 weeks of treatment initiation 2

Step 3: Management of Acute Episodes

• Epinephrine: For acute mast cell activation attacks involving hypotension, wheezing, or laryngeal edema 3
  • Should be administered intramuscularly in a recumbent position
  • Essential for treating cyanotic episodes and recurrent anaphylactic attacks

Step 4: Advanced Treatment for Severe Cases

• Cytoreductive therapy: Generally reserved for aggressive systemic mastocytosis, mast cell leukemia, and mast cell sarcoma 4
  • Strongly discouraged for cutaneous disease due to its benign nature and high rate of spontaneous regression 3
  • May be considered in extremely rare cases with life-threatening symptoms that don't respond to conventional therapy

Special Considerations

Pediatric Mastocytosis

• Symptoms are usually more severe in the first 6-18 months after onset of lesions 3
• Most cases follow a benign course with high rates of spontaneous regression
• Follow-up should be scheduled every 6-12 months 1
• Parents should be educated about the condition and informed about the possibility of evolution to systemic form in a minority of cases 3

Perioperative Management

• Continue scheduled maintenance medications
• Pre-medication with H1 antihistamines is recommended 1
• Communication with healthcare providers about the diagnosis is crucial to prevent life-threatening episodes during procedures 3

Monitoring

• Baseline serum tryptase levels should be recorded before starting therapy 3
• Elevated tryptase levels (>20 μg/L) indicate increased mast cell burden and require closer monitoring 3
• Regular follow-up is essential to assess treatment response and disease progression

Treatment Efficacy and Pitfalls

• The combination of H1 and H2 antihistamines remains the cornerstone of symptomatic treatment 5
• Cromolyn sodium has shown similar efficacy to the combination of chlorpheniramine plus cimetidine for both cutaneous and systemic symptoms 2
• A common pitfall is inadequate dosing of antihistamines; higher-than-standard doses may be required in some patients
• Another pitfall is failure to recognize and treat comorbidities like osteoporosis, which can occur in systemic mastocytosis

By following this stepwise approach to treatment, most patients with mastocytosis can achieve good symptom control and maintain quality of life.