From the Guidelines
Mastocytosis patients should be referred to specialized centers with expertise in the management of mastocytosis and multidisciplinary collaboration with subspecialists is recommended. Mastocytosis is a heterogeneous group of disorders comprising cutaneous mastocytosis, systemic mastocytosis, and mast cell sarcoma, associated with a variety of symptoms related to the release of mast cell mediators and mast cell tissue infiltration 1. The condition results from genetic mutations, particularly in the KIT gene, which controls mast cell growth and function, causing these cells to accumulate abnormally in tissues and release excessive amounts of inflammatory chemicals.
Symptoms and Classification
Mastocytosis can be classified into cutaneous mastocytosis (affecting primarily the skin) and systemic mastocytosis (affecting internal organs). Symptoms vary widely depending on the type and severity but often include:
- Skin lesions
- Flushing
- Itching
- Abdominal pain
- Diarrhea
- Bone pain
- Anaphylactic reactions
Treatment
Treatment typically involves managing symptoms with:
- Antihistamines like cetirizine (10mg daily) or fexofenadine (180mg daily) to block histamine effects
- Mast cell stabilizers such as cromolyn sodium (200mg four times daily)
- Avoiding triggers that cause mast cell degranulation like certain foods, alcohol, extreme temperatures, and specific medications
- For severe cases, tyrosine kinase inhibitors like midostaurin may be prescribed
- Patients should carry emergency epinephrine (EpiPen) for potential anaphylactic reactions, as recommended in the management of pediatric mastocytosis 1.
Management Approach
The NCCN Guidelines for Systemic Mastocytosis provide evidence- and consensus-based recommendations for the diagnosis and comprehensive care of patients with systemic mastocytosis 1. A multidisciplinary approach is crucial, including collaboration with allergists for the management of anaphylaxis and drug hypersensitivities, anesthesiologists for invasive procedures or surgery, and high-risk obstetricians for pregnancy. The guidelines are updated annually to reflect the latest research and clinical practices.
Pediatric Considerations
In pediatric-onset mastocytosis, the disease often presents with cutaneous manifestations, and the course can be variable 1. The need for intensive therapy in pediatric mastocytosis is exceptional, and treatment should be tailored to the individual child's needs, with consideration of the potential long-term effects of antiproliferative agents 1.
From the Research
Definition and Symptoms of Mastocytosis
- Mastocytosis is a disorder characterized by the accumulation of abnormal mast cells in various organs, including the skin, bone marrow, and visceral organs 2, 3.
- The symptoms of mastocytosis can include flushing, pruritus, nausea, vomiting, abdominal pain, diarrhea, vascular instability, and headache, which can be divided into cutaneous and systemic manifestations 2.
- The clinical features of mastocytosis can be puzzling and may lead to delayed diagnosis, especially in cases without typical skin lesions 3.
Diagnosis and Classification of Mastocytosis
- The diagnosis of mastocytosis is based on the World Health Organization criteria, which include tryptase level, histopathological and immunophenotypic evaluation of mast cells, and molecular analysis 4, 5, 3.
- Mastocytosis can be classified into different categories, including cutaneous mastocytosis, indolent systemic mastocytosis, and advanced systemic mastocytosis, which includes aggressive systemic mastocytosis, systemic mastocytosis with associated hematological neoplasm, and mast cell leukemia 4, 5, 3.
Treatment and Management of Mastocytosis
- The treatment of mastocytosis aims to avoid mast cell degranulation, inhibit the actions of mast cell mediators, and reduce the burden of the disease 2, 4, 5.
- Treatment options for mastocytosis include H1 and H2 antihistamines, proton pump inhibitors, anti-leukotriene agents, and injectable epinephrine for anaphylaxis prevention and symptom control 2, 6.
- Cytoreductive therapy, including interferon alpha, glucocorticoids, and cladribine, may be necessary for patients with advanced systemic mastocytosis 2, 4, 5.
- Small-molecule inhibitors, such as midostaurin and avapritinib, have shown promise in targeting mutant-KIT in patients with systemic mastocytosis 4, 5.