A Clinical Yardstick for Managing Indolent Systemic Mastocytosis (ISM)
Welcome to the Allergy, Asthma & Immunology Innovations podcast. In this new episode of The Itch Review, in which we highlight recent research in allergy and immunology, focuses on indolent systemic mastocytosis (ISM). It explores new clinical recommendations for its diagnosis and treatment.
Our co-hosts, Payel Gupta, MD and Kortney, are joined by allergist Michael Blaiss, MD, to review a recent journal article on ISM: “Management of indolent mastocytosis and mast cell activation syndrome – A clinical yardstick.” It was published June 2025 in the Annals of Allergy, Asthma & Immunology.
This is the second of two episodes focusing on this study and indolent systemic mastocytosis. The first episode covers mast cell activation syndrome.
You can listen to the podcast on ItchPodcast.com or download it for listening anytime, anywhere, at:
This podcast is for informational purposes only and does not substitute professional medical advice. Any mention of brands is also informational and not an endorsement. Always consult with your healthcare provider for any medical questions or concerns.
Thanks to Blueprint Medicines for sponsoring this episode.
What is indolent systemic mastocytosis?
Mast cells are part of your immune system and help fight infection. But with ISM, people have too many mast cells, and they release chemicals too often. This can cause symptoms like rashes, stomach issues, tiredness, or even serious allergic reactions.
In this podcast, our hosts talk about how doctors find out if someone has ISM and how it can be managed.
What we cover in this episode about ISM
- What is a yardstick and how does it help doctors make decisions?
- Mast cell disease groupings: clonal (like ISM), allergic, and unknown cause.
- How ISM is diagnosed: tryptase blood tests, KIT D816V mutation testing, HaT genetic testing, and bone marrow biopsy.
- Treatments for ISM: antihistamines, mast cell stabilizers, leukotriene blockers, and venom allergy care.
- New targeted medication: how avapritinib works to treat ISM symptoms by blocking the KIT mutation.
Timestamps for this episode about diagnosing and treating ISM
01:42 – Types of mast cell disorders
05:11 – What is indolent systemic mastocytosis
07:38 – Common ISM symptoms
09:02 – How doctors find out if you have ISM
15:46 – What is HaT and why it matters
20:56 – How doctors treat ISM
24:47 – Brain fog and anxiety in ISM
26:16 – More treatments for ISM
30:12 – Medicine called avapritinib
33:03 – Final thoughts from the doctors
Resources about mast cell disease
- Mast Cell Disease Toolkit
- What is Mastocytosis? Types, Symptoms, and Treatment
- Mast Cell Disease Glossary of Terms
