Indolent systemic mastocytosis (ISM) is the most common form of systemic mastocytosis (SM), a condition characterized by the overproduction and over-activation of mast cells.
Mast cells are a type of white blood cell that, under normal circumstances, help the body fight infections. The abnormal mast cells that arise with systemic mastocytosis build up in organs and tissues throughout the body and, when they become active, release large amounts of histamines.
Histamines are chemicals involved in inflammatory and immune responses, including allergic reactions. The release of histamines is what drives ISM symptoms, such as skin itching, skin rash, flushing, and gastrointestinal upset.
The severity and frequency of symptoms can vary significantly between individuals. ISM is the mildest form of the condition, though it can progress into more severe types, and it also carries a risk of anaphylaxis, a life-threatening allergic reaction. It’s recommended that a person with any form of SM carry two epinephrine injectors in case of anaphylaxis.
Treatment for ISM
ISM typically does not require the more intensive therapies and procedures that may be recommended in the treatment of more severe types of systemic mastocytosis. Treatment of ISM focuses on managing symptoms and monitoring for signs of progression.
Treatment is individualized, meaning it varies from person to person. However, all treatment plans will include strategies to avoid triggers, or things that can activate mast cells and cause symptoms to worsen. Common triggers include alcohol, insect bites, stress, physical exertion, sudden changes in temperature, certain medications (like NSAIDs), and spicy foods. A person should work with their healthcare provider to identify their triggers and take steps to minimize exposure.
Medications also play an important part in managing ISM. These include antihistamines to control allergic reactions, mast cell stabilizers (which prevent mast cells from releasing histamine), and medicines to address specific symptoms, such as topical emollients to keep skin moisturized and less prone to triggers.
Treatment is also evolving to include targeted therapy drugs. These medications target specific enzymes and pathways that lead to mast cell production and activation.
Working with multiple healthcare providers
People with ISM will often benefit from working with multiple healthcare providers. This is called “interdisciplinary care” or “multidisciplinary care.” Members of a healthcare team will vary depending on a person’s specific symptoms and needs.
A care team may include:
- Hematologist
- Allergist/immunologist
- Primary care provider
- Dermatologist
- Gastroenterologist
- Cardiologist
- Orthopedist
- Registered dietitian
- Nurses
- Pharmacists
It's important that the different members of your healthcare team are in communication with one another. This is called care coordination, and it can be a challenge of treating conditions like ISM. Here are two strategies that can help:
Designate a point person
Communicating with multiple healthcare providers about different aspects of ISM care can be overwhelming. Consider designating one healthcare provider as your "point person."
This provider should maintain an overview of all aspects of your ISM care, including diagnosis information, contact details for other providers, and treatment information. Your point person may be a specialist such as a hematologist or allergist/immunologist, or your primary care provider.
Organize a personal health record
Maintaining an organized personal health record helps ensure all providers have access to the information that they need. This file should contain:
- Test results including results from blood tests, bone scans, imaging tests, biopsies, and genetic testing
- Evaluations and workups from specialists
- Treatment records, including medications you've been prescribed and medical procedures
- Contact information for all of your healthcare providers
- Insurance information
- Copies of bills, receipts, explanation of benefits documents, and other information related to the financial aspects of treatment
Include your own notes from appointments, including questions you've asked and information provided by your healthcare providers. It’s also recommended to keep a journal that tracks symptoms and potential triggers.
Keeping this information organized can also be helpful any time you need to contact a health insurance provider or when seeing a new specialist.
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