What is the initial treatment for mastocytosis?

Initial Treatment for Mastocytosis

The initial treatment for mastocytosis should focus on stabilizing mast cell mediator release and blocking their effects through H1 and H2 antihistamines, which form the cornerstone of symptomatic management. 1

Treatment Approach Based on Disease Type

First-Line Therapy

• H1 antihistamines (such as diphenhydramine, hydroxyzine, or cetirizine) are the primary treatment to decrease pruritus, flushing, urticaria, and tachycardia 1
• Combined treatment with H1 and H2 antihistamines (ranitidine, famotidine) is effective for controlling severe pruritus, wheal formation, and managing gastric hypersecretion 1
• Oral cromolyn sodium has proven effective for controlling gastrointestinal symptoms (diarrhea, abdominal pain, nausea, vomiting) and may help with cutaneous symptoms 1, 2
• Avoidance of known triggering factors is essential to prevent mast cell activation episodes 1

Acute Mast Cell Activation Management

• For acute mast cell activation attacks involving hypotension, wheezing, or laryngeal edema, epinephrine should be administered intramuscularly in a recumbent position 1
• Cyanotic episodes and recurrent anaphylactic attacks should be treated with epinephrine 1

Special Considerations

Gastrointestinal Symptoms

• If H2 antihistamines cannot control gastrointestinal symptoms, proton pump inhibitors may be recommended 1
• Oral cromolyn sodium has shown clinical improvement within 2-6 weeks of treatment initiation for gastrointestinal manifestations 2

Cutaneous Manifestations

• Water-soluble sodium cromolyn cream or aqueous-based sodium cromolyn skin lotion can decrease pruritus and flaring of lesions 1
• For bullous diffuse cutaneous mastocytosis in children, oral methoxypsoralen therapy with PUVA has been reported to be effective, even in patients with life-threatening mast cell mediator release episodes 1

Systemic Mastocytosis

• The benefit of cromolyn sodium 200 mg QID is similar to combination therapy with chlorpheniramine plus cimetidine for both cutaneous and systemic symptoms 2
• For severe cases of systemic mastocytosis during pregnancy refractory to conventional therapy, interferon-alfa can be considered, while cladribine or tyrosine kinase inhibitors should be avoided 1

Important Caveats

• Cytoreductive therapy is strongly discouraged except in selected cases with life-threatening aggressive variants of mastocytosis 1
• The need for intensive therapy in pediatric mastocytosis is exceptional, with most cases following a benign course 1
• High doses of H1 antihistamines may cause cardiotoxicity, requiring careful dosing 1
• Progressive introduction of cromolyn sodium helps reduce side effects such as headache, sleepiness, irritability, abdominal pain, and diarrhea 1

Perioperative Management

• Multidisciplinary management is recommended with involvement of surgical, anesthesia, and perioperative medical teams 1
• Pre-anesthetic treatment with anxiolytic agents (benzodiazepines), antihistamines (H1 and H2 blockers), and possibly corticosteroids can reduce the frequency/severity of mast cell activation events 1
• Certain perioperative drugs are considered safer, including propofol, sevoflurane, isoflurane, fentanyl, remifentanil, lidocaine, and bupivacaine 1
• Muscle relaxants atracurium and mivacurium, and succinylcholine should be avoided 1

By following this treatment algorithm and recognizing the specific disease patterns, most patients with mastocytosis can achieve good symptom control and improved quality of life.