Newly Diagnosed With Indolent Systemic Mastocytosis: What to Expect

Being newly diagnosed with indolent systemic mastocytosis (ISM) can bring relief and worry at the same time. There’s finally a name for what’s been happening, but there could also be a long list of new questions. Here’s what usually comes next.

What this diagnosis means, and what it does not

ISM is the slow-moving form of systemic mastocytosis, and the most common one in adults. Only about 3 to 5 percent of people with ISM go on to develop a more advanced form. Life expectancy is close to that of the general population.^1-3

There is no cure for ISM. However, there are ways to manage the symptoms and complications that may arise.^1,3

What happens next

Expect monitoring rather than a single course of treatment. Your care team will check your blood and urine at intervals.^1,4

A small number of specialized centers also offer a home kit for collecting blood and urine while you are having symptoms, so your team can see what is happening at the peak of those symptoms. It is worth asking whether your care team or healthcare facility does this.⁵

Your treatment plan will be built around whichever symptoms affect you most. That takes some trial and adjustment, so early appointments may feel more like tuning than fixing.^1,4

Building your care team

Treating systemic mastocytosis can involve a lot of different specialties. Newly diagnosed people generally need consultations with 4 specialists:⁶

• Hematologist
• Dermatologist
• Immunologist
• Gastroenterologist

Depending on your symptoms, your team may also bring in specialists in allergies, medical genetics, hepatology, neurology, endocrinology, and pathology.⁵

Because ISM is rare and needs coordinated care across all of these areas, being monitored at a center that specializes in mastocytosis is recommended whenever possible.⁷

Making an emergency plan

It is very important to have a plan for ISM symptoms that may become emergencies with little or no warning.

Everyone with a mast cell disease should carry 2 doses of epinephrine at all times, even without a history of a severe reaction.^4,6

ISM patients are also advised to wear medical alert identification – such as a medical bracelet – that names your condition and any drugs you cannot take or be given. Your healthcare team can advise you on any other details you should include.^1,4

Tell the people you are around most what a reaction looks like and where you keep your epinephrine. In an emergency, you may not be the one able to explain it.

Getting your bone health checked

Bone loss is common in ISM and easy to overlook because it causes no symptoms until it’s serious. A bone density scan is recommended at diagnosis and again during follow-up. Getting enough calcium and vitamin D matters, too. Ask about this early if no one on your care team has raised the issue.^6,7

Tracking your symptoms and triggers

Triggers are different for every person, so no one can give you a complete list of things you must avoid. It is important to determine your unique set of triggers and allergies/sensitivities, because avoiding them lowers your risk of an attack or flare.^1,4

Note what happened before a flare: what you ate, the temperature, your stress level, and anything new you took. Patterns emerge over weeks that can be invisible day to day.¹

Questions to ask your doctor

Try bringing a list of questions to your next appointment. Writing the answers down can help you keep them fresh in your mind rather than having to try to remember them afterward.

A few useful questions to ask may include:^1,6,7

• Which type of systemic mastocytosis do I have?
• What symptoms would mean my condition is changing?
• Which treatments make sense for my type, and what are the side effects?
• Should I have a bone density scan, and how often?
• How many doses of epinephrine should I carry, and when exactly should I use one?
• Which drugs should I avoid?
• Are there clinical trials I could join?

You are not alone

ISM is rare, and that can feel isolating in a way that more common conditions are not. There are communities of people managing the same thing, and finding them can be very helpful in taking care of your mental health.
Keep asking questions at your appointments, especially the ones that feel too small to bother anyone with. Those are often the ones that change your plan.