Ep. 127: Management of indolent mastocytosis - A clinical yardstick
Part of the series: The Itch Review
LISTEN TO EPISODE 127: Apple Podcast • Spotify • Amazon Music
This podcast was made in partnership with Allergy & Asthma Network.
We thank Blueprint Medicines for sponsoring this episode. While they support the show, all opinions are our own, and sponsorship doesn’t influence our content or editorial decisions. Any mention of brands is for informational purposes and not an endorsement.
Indolent Systemic Mastocytosis (ISM) is a rare but often underrecognized clonal mast cell disorder. From random hives to gut pain and brain fog, ISM can feel like a medical mystery.
We continue our review of “Management of indolent mastocytosis and mast cell activation syndrome - A clinical yardstick,” published in June 2025 in The Annals of Allergy, Asthma & Immunology. This is Part 2 of our discussion, with a focus on indolent systemic mastocytosis. We look at what causes it, how it’s diagnosed, and how to manage symptoms and improve quality of life.
In this episode, we break down this complex mast cell disease and how doctors use baseline serum tryptase, KIT D816V testing, and HaT screening to find answers. Plus, we explain how treatments like antihistamines, mast cell stabilizers, and avapritinib can help people live better with ISM.
What we cover in our episode about indolent systemic mastocytosis:
Yardsticks explained: Why the ACAAI uses yardsticks as practical, interim guidelines before full consensus statements are available.
Understanding mast cell diseases: The difference between primary (clonal), secondary (allergic), and idiopathic mast cell disorders.
Diagnosing ISM: KIT D816V mutation, WHO/ICC criteria, baseline serum tryptase, and when to test for hereditary alpha-tryptasemia (HaT).
Symptoms of ISM: Why symptoms vary and how they can involve multiple systems, including skin, GI tract, cardiovascular, and even neuropsychiatric.
Management strategies: Trigger avoidance, antihistamines, leukotriene blockers, sodium cromolyn, aspirin therapy, and when venom immunotherapy is appropriate.
Targeted treatment: How avapritinib works and what the PIONEER study shows about its role in ISM.
More resources about mast cell disorders
Other podcast episodes about mast cell disease
Ep. 126: Management of mast cell activation syndrome - A clinical yardstick
Ep. 121: Avapritinib vs Placebo in Indolent Systemic Mastocytosis - PIONEER Trial
Ep. 118: The ISM Disconnect - Do Patients and Providers Agree on Symptom Control?
Ep. 70 How do stress and low histamine diets impact mast cell disease?
Ep. 63: Mast Cell Diseases & Systemic Mastocytosis: The Basic Science
Watch more episodes about mast cell disease
The Itch Review, hosted by Dr. Gupta, Kortney, and Dr. Blaiss, explores allergy and immunology studies, breaking down complex research in conversations accessible to clinicians, patients, and caregivers. Each episode provides key insights from journal articles and includes a one-page infographic in the show notes for easy reference.
Timestamps
Our episode discusses the diagnosis and treatment of mast cell disease in the yardstick from 2025
01:42 Mast cell disease classification
05:11 Understanding systemic mastocytosis
07:38 Indolent systemic mastocytosis symptoms
09:02 ISM diagnosis: tryptase, KIT, HaT
15:46 Hereditary alpha-tryptasemia in ISM
20:56 ISM treatment to control mast cell mediators
24:47 Neuropsychiatric symptoms in ISM
26:16 Other symptom management for ISM
30:12 Avapritinib for indolent systemic mastocytosis
33:03 Expert takeaways on ISM care
