This handout is for mast cell activation syndrome (mcas). Your care team identified this based on: recurrent episodic typical mast-cell symptoms involving >=2 organ systems (valent 2020 pmid 33261124).
Other reasons your team may use this plan: recurrent unexplained anaphylaxis without an identifiable ige trigger — idiopathic anaphylaxis as a form of mcas (giannetti 2020 pmid 32276688); elevated basal serum tryptase (>11.4 ng/ml) — workup for clonal mast-cell disease vs hαt (lyons 2016 pmid 27749843; chovanec 2023 pmid 36170795); family history of hereditary alpha-tryptasemia or systemic mastocytosis — genetic and clonal workup entry.
Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.
| Medication | Starting dose | How | When | What it does |
|---|---|---|---|---|
| trigger_avoidance_inventory | — | — | — | Valent 2020 (PMID 33261124) — heat, exercise, alcohol, NSAIDs, opioids, vancomycin, NMBA, Hymenoptera, foods; personalised inventory drives prevention. |
| epinephrine | 0.15 mg IM (peds <25 kg) / 0.3 mg IM (>=25 kg) | IM lateral thigh | PRN for systemic reaction; may repeat 5-15 min | Valent 2020 (PMID 33261124) — anaphylaxis-grade MCAS events require IM epinephrine first-line; two auto-injectors carried; technique re-taught. |
| written_mcas_action_plan | — | — | — | Patient education on early-symptom recognition + step-up therapy + when to use auto-injector + when to seek care. |
Plan: MCAS — H1+H2 antihistamine foundation + cromolyn + LTRA + ketotifen + omalizumab; clonal disease via heme-onc
Contact your care team if any of the following happen:
Call 911 or go to the nearest emergency room right away if you have:
Lifelong chronic-disease maintenance: trigger avoidance + premedication for unavoidable triggers (e.g., contrast studies, surgery, dental procedures — H1 + H2 + cromolyn + corticosteroid premedication regimen), auto-injector + action plan, family screening for HαT, periodic re-evaluation for clonal MC disease emergence.
Guideline: Valent et al 2020 - MCAS Diagnosis, Classification and Management (Int J Mol Sci 2020-11; PMID 33261124) + Giannetti/Akin/Castells 2020 - Idiopathic anaphylaxis as a form of MCAS (J Allergy Clin Immunol Pract 2020-04; PMID 32276688) + Lyons 2016 - TPSAB1 copy-number and hereditary alpha-tryptasemia (Nat Genet 2016-10; PMID 27749843) + Chovanec/Lyons 2023 - personalised tryptase reference ranges (Blood Adv 2023-05; PMID 36170795)