Why Does MCAS Not Respond to Standard Treatment? The Four Mechanistically Distinct Patterns — What this means for treatment

A treatment approach anchored in the four-pattern stratification looks different from standard MCAS care. The first task is stratification. The second is intervention at the appropriate level. The third is sequenced stabilization. For Pattern A cases, the sequence is roughly: identify the barrier driver (post-infectious, post-antibiotic, ongoing inflammatory exposure), address the upstream cause if it is still present, work the gut substrate per the Host Capacity Model approach , and add mucosal mast cell stabilization (cromolyn, quercetin) as containment while the barrier work proceeds. Symptomatic relief often becomes evident in weeks. Durable response typically takes three to six months as barrier integrity is restored. For Pattern B cases, the sequence is roughly: address the autonomic state directly (vagal tone work, autonomic conditioning, addressing any deconditioning, working with POTS specialists if needed), support the cholinergic anti-inflammatory pathway, and add stabilization as containment. Pattern B often has the fastest meaningful response of the four patterns once the right axis is identified. Patients describe the change as "feeling like myself again" within weeks. For Pattern C cases, the sequence is roughly: confirm the exposure with testing and environmental investigation, remove the exposure (often the hardest part for patients with limited resources), sup