MCAS Diagnostic Debate Exposes Gaps in Care and Access
Experts describe MCAS as a spectrum of symptoms from hives and flushing to abdominal pain and anaphylaxis, with two competing diagnostic approaches: a stricter consensus 1 requiring recurrent multisystem symptoms plus objective mediator elevation, and a broader consensus 2 that recognizes more signs without always needing mediator tests. Testing—especially tryptase—can miss cases, and disagreement about interpretation fuels under- and over-diagnosis, while access barriers and misinformation complicate care. Treatments focus on symptom control (antihistamines, mast cell stabilizers, leukotriene modifiers, sometimes omalizumab), with epinephrine for severe reactions, and clinicians emphasize careful evaluation to avoid mislabeling or overlooking other causes.