Why Allergists Overlook Mast Cells

Haylie Pomroy and Dr. Theoharis Theoharides discuss why patients with chemical sensitivities are often routed from primary care to allergists, yet many allergists do not recognize Multiple Chemical Sensitivity (MCS) or its overlap with mast cell activation, leaving patients without a clear diagnosis or support. They note that the clinician who documents the diagnosis is the one who assigns the billing/ICD code; when MCS isn’t acknowledged, patients may receive vague codes or none at all, which can hinder care and insurance coverage. The conversation highlights the need for clinician awareness of mast cell biology in chemical sensitivity, more practical diagnostic pathways, and supportive management for those with suspected MCAS-related sensitivities.