What is the treatment for a mastocytosis break out?

Treatment of Mastocytosis Flare (Breakout)

For acute mastocytosis flares, immediately administer H1 antihistamines (such as diphenhydramine, hydroxyzine, or cetirizine) to control pruritus, flushing, urticaria, and tachycardia, and if the episode involves hypotension, wheezing, or laryngeal edema, give intramuscular epinephrine in a recumbent position. 1, 2

Immediate Management of Acute Mast Cell Activation

Life-Threatening Symptoms

• Epinephrine IM is the first-line treatment for acute attacks involving hypotension, wheezing, or laryngeal edema 1, 2
• Administer in a recumbent position to prevent cardiovascular collapse 1
• Cyanotic episodes and recurrent anaphylactic attacks require epinephrine administration 1

Non-Life-Threatening Symptoms

• H1 antihistamines are the primary treatment for controlling pruritus, flushing, urticaria, and tachycardia 1, 2
• Effective options include diphenhydramine, hydroxyzine, and cetirizine 1
• Both sedating and non-sedating antihistamines may be used depending on symptom severity and timing 1

Escalation for Severe or Refractory Symptoms

Combined Antihistamine Therapy

• Add H2 antihistamines (ranitidine or famotidine) when H1 antihistamines alone fail to control severe pruritus and wheal formation 1, 2
• This combination is particularly effective for severe cutaneous symptoms 1

Gastrointestinal Symptoms

• Start with H2 antihistamines (ranitidine or famotidine) for gastric hypersecretion and peptic symptoms 1, 2
• If H2 antihistamines fail to control GI symptoms, escalate to proton pump inhibitors 1, 2

Topical Therapy for Cutaneous Lesions

• Water-soluble sodium cromolyn cream or aqueous-based sodium cromolyn skin lotion can decrease pruritus and flaring of lesions 2
• Cromolyn sodium oral solution (200 mg QID) is FDA-approved for mastocytosis and improves diarrhea, flushing, headaches, vomiting, urticaria, abdominal pain, nausea, and itching 3
• Clinical improvement with oral cromolyn typically occurs within 2-6 weeks of treatment initiation 3

Critical Trigger Avoidance

Identify and avoid specific triggers to prevent future flares 1, 2:

• Hot temperatures (control bath, shower, swimming pool temperature) 1
• Cold temperatures (to a lesser extent) 1
• Mechanical pressure on skin (can cause local erythema, edema, or even blistering in diffuse cutaneous mastocytosis) 1
• Anxiety and stress 1
• Avoid ketorolac entirely (associated with lethal idiosyncratic reaction in adults with mastocytosis) 1
• NSAIDs, certain opioids (meperidine and morphine more problematic than fentanyl), and specific anesthetic agents 1

Important Caveats

Monitoring Requirements

• Check baseline serum tryptase levels 1
• Tryptase >20 μg/L indicates increased mast cell burden and requires close observation, evaluation, and possibly hospitalization 1
• During acute episodes, tryptase elevation over baseline suggests mast cell activation 1

Cardiotoxicity Risk

• High doses of H1 antihistamines may cause cardiotoxicity 1, 2
• Use appropriate dosing based on age and weight 1

When NOT to Use Cytoreductive Therapy

• Cytoreductive therapy is strongly discouraged except in life-threatening aggressive variants of mastocytosis 1, 2
• The generally benign nature of cutaneous disease and high rate of spontaneous regression (especially in children) makes aggressive treatment unnecessary in most cases 1

Coagulation Considerations

• Mast cells contain heparin, which may cause slightly prolonged PT and PTT 1
• This is generally not clinically significant but should be considered before invasive procedures 1

Patient Education Priorities

• Educate patients and caregivers about trigger avoidance 1
• Ensure availability of emergency medications (epinephrine auto-injector for severe cases) 1
• Alert healthcare providers, teachers, and caregivers about the diagnosis and potential risks 1
• Emphasize that cutaneous mastocytosis is not contagious 1