The Spectrum of Mast Cell Activation Syndromes

Mast cell activation syndromes are a rare group of allergic disorders that can present with severe and recurrent symptoms and be difficult to diagnose and manage. While the clinical signs and symptoms are similar for all variants of MCAS, MCAS can  result from primary (clonal), secondary (non-clonal) or idiopathic causes. The clinician  must conduct a detailed history and physical exam and should consider a laboratory evaluation looking for signs of mast cell activation (tryptase, urine studies) and/or end organ involvement in any patient who presents with severe or recurrent anaphylaxis, as a mast cell activation syndrome may be on the differential diagnosis. Multi-disciplinary care involving general practitioners, hematology/oncology, allergy/immunology and gastroenterology may be necessary.