Why Does MCAS Not Respond to Standard Treatment? The Four Mechanistically Distinct Patterns — The recognition pattern: how to tell which is operating

The four patterns produce overlapping symptoms but distinguishable signatures. The questions that help stratify a case quickly are: Are the reactions dominantly tied to food and meals? Pattern A signature. Are the reactions tied to posture, sleep, stress, or autonomic state? Pattern B signature. Are the reactions tied to location, building, or exposure? Pattern C signature. Is the baseline tryptase elevated or is there family history of similar symptoms? Pattern D signature. Many cases have features of more than one pattern. The clinical task is to identify which is dominant, not to force the case into a single bucket. A case that is 70 percent Pattern A and 30 percent Pattern B benefits from barrier work first and autonomic work second. A case that is reversed benefits from the reverse sequencing. The patterns also tend to evolve. Pattern A often comes first, in the wake of antibiotic exposure or post-infectious gastroenteritis. Pattern B often emerges later, as the chronic illness state degrades autonomic regulation. Pattern C is usually obvious once it is being looked for. Pattern D is usually present from earlier in life if it is going to be present at all.