Introduction: Mastocytosis, a heterogeneous group of disorders, is characterized by an abnormal increase in the number of mast cells that is limited to the skin (cutaneous mastocytosis), involving extracutaneous tissues (systemic mastocytosis), or presenting as solid tumours (mastocytoma and mast cell sarcoma). Recent studies estimate that 1 in 10,000 people are diagnosed with mastocytosis. Although prompt diagnosis and appropriate management are crucial, little is known about the natural history and currently there are no established management guidelines. We have conducted a systematic review to assess the natural history and management of different mastocytosis subtypes.
Methods: A systematic review and meta-analysis were conducted using the PubMed and Ovid database of studies published in English and French over the last fifteen years, from January 2001 to December 2016. Keywords 'Cutaneous mastocytosis', 'Systemic mastocytosis', 'pathophysiology', 'clinical course', 'prognosis', 'drug therapy', and 'therapy' were searched. Rate of complete resolution was subjected to pooled analysis for different mastocytosis subtypes. Meta-analysis was conducted using Stata version 12.0.
Results: We reviewed 634 papers, of which 5 were included in the analysis of resolution, and 138 were included in the assessment of management. Pooled estimate for rate of complete resolution varied depending on the mastocytosis subtype. In cutaneous mastocytosis, the complete resolution rate for mastocytoma was 10% per year (95% CI: 4.8%, 15.1%) while the rate for urticaria pigmentosa was 1.9% per year (95% CI: -0.5%, 4.3%). Diffuse cutaneous mastocytosis and systemic mastocytosis subtypes did not show evidence of complete resolution in the studies reviewed. Treatment of cutaneous and systemic mastocytosis is purely symptomatic with topical corticosteroids, antihistamines, omalizumab and imatinib being common choices.
Conclusion: Rate of resolution of mastocytosis is only shown in urticaria pigmentosa and mastocytoma. Better management guidelines are required to improve the health of these patients.
Keywords: Mastocytosis; cutaneous/systemic; histamine antagonists/therapeutic use; imatinib/therapeutic use; mastocytosis/drug therapy; omalizumab/therapeutic use; prognosis.