Systemic mastocytosis treatment guidelines

Systemic mastocytosis—Overview

A rare clonal condition, systemic mastocytosis is characterised by the abnormal accumulation of mast cells in the bone marrow, skin, and various organs. Triggered mast cells release histamine and tryptase, causing symptoms such as flushing, itching, anaphylaxis, diarrhoea, abdominal discomfort, bone pain, and fatigue. Symptom management, trigger avoidance, and specific KIT inhibitors, such as avapritinib, are needed for advanced forms.

Urticaria pigmentosa.

Systemic mastocytosis symptoms

An uncommon condition, systemic mastocytosis, causes aberrant mast cells to amass in organs and release excessive histamine and other substances. This can cause many symptoms that mimic allergic reactions or organ malfunction.

Symptoms Common

• Skin-related
• Urticaria pigmentosa—itchy rashes
• Flushing (skin redness and warmth)
• Rubbing skin lesions causes swelling (Darier's sign).

The digestive system

• Cramps or abdominal pain
• Diarrhea
• Nausea, vomiting

Allergic/systemic responses

• Severe allergic response
• Blood pressure is low
• Fast heartbeat
• Dizziness or fainting

Others symptoms

• Painful bones or osteoporosis
• Fatigue
• Headaches
• Large liver, spleen, or lymph nodes
• Blood disorders like anemia

Important Notes

Symptoms differ by mast cell location (skin, bone marrow, digestive tract, liver, spleen). Alcohol, bug stings, stress, and pharmaceuticals are triggers. From moderate skin irritation to life-threatening anaphylaxis.

Conditions related to mastocytosis?

Mast cell accumulation and excessive histamine release can cause mastocytosis in many circumstances. The overview is structured as follows:

Mastocytosis-related conditions

• Allergic diseases
• Repeated anaphylaxis (from insect stings, drugs, or foods)
• Increased or persistent severe allergic responses

Gastrointestinal issues

• Chronic diarrhea
• Peptic ulcer disease (histamine-induced acid generation)
• Malabsorption disorders

Connective tissue and bone diseases

• Osteoporosis
• Osteopenia
• Fractures or bone discomfort

Haematology issues

Systemic mastocytosis with accompanying hematologic neoplasms, commonly myelodysplastic syndromes or leukaemias

• Anaemia or blood cell abnormalities
• Problems with organs
• Liver enlargement
• An enlarged spleen
• Swollen lymph nodes

Disorders of the skin

• Urticaria pigmentosa (brown skin lesions that itch or swell in touch)
• Chronic flushing

Key Point

Mastocytosis can be cutaneous or systemic, affecting the accompanying disorders. Systemic forms often cause hematologic disorders and organ failure.

Also, read https://www.medicoverhospitals.in/diseases/systemic-mastocytosis/.

Avoid what foods with mastocytosis?

Mastocytosis can be worsened by meals that contain high histamine levels or activate mast cells. While triggers vary by person, these are the most popular foods to avoid:

Limit or avoid these foods

• Histamine-rich foods
• Vinegar, soy sauce, sauerkraut, kefir, yogurt
• Wine, beer, champagne, kombucha
• Bacon, sausages, and ham
• Aged cheeses

Histamine-releasing foods

• Oranges, grapefruit, lemons
• Strawberries
• Papaya, pineapple, bananas
• Eggplant, peppers, tomatoes
• Spinach
• Avocados
• Chocolate
• Peanuts, cashews, walnuts
• Shellfish

Others may trigger

• Beer, pastry, and bread contain yeast.
• Artificial colours and preservatives
• Wheat germ
• Pickled foods and vinegar salad dressings

Important Notes

• Mastocytosis affects food tolerance differently.
• Food diaries can reveal triggers.
• A low-histamine diet is recommended, but a doctor should customize it.

What causes systemic mastocytosis?

Systemic mastocytosis is caused by mast cell proliferation and buildup in the bone marrow, skin, liver, spleen, and gastrointestinal system. The immune system's mast cells fight pathogens and allergies. Systemic mastocytosis causes allergy symptoms and organ malfunction due to uncontrolled cell proliferation and histamine and other chemical production.

Root Causes

• Mutations in genes
• A mutation in the KIT gene (particularly KIT D816V) causes mast cell activation and uncontrolled proliferation, the most prevalent cause.
• Dysregulated immune system
• Overactive mast cells release histamine and other mediators without stimuli.

Triggers that aggravate symptoms

• Alcohol, insect bites, drugs, physical stress, and emotional stress can activate mast cells and cause symptoms.

Systemic mastocytosis diagnosis

Systemic mastocytosis (SM) is diagnosed through clinical evaluation, laboratory tests, imaging, and genetic analysis. Doctors use precise criteria to diagnose the disease since symptoms overlap with other allergic or hematologic diseases.

Diagnosis steps

• Health history and exam
• Review symptoms such as flushing, anaphylaxis (a severe allergic reaction), and lesions on the abdomen, bones, and skin.
• The doctor checks the skin for mast cell abnormalities, such as urticaria pigmentosa.

Laboratory tests

• Blood and urine tests: High mast cell activity marker tryptase.
• Measurement of histamine or metabolites.

Marrow biopsy

• Gold standard for diagnosis.
• Found aberrant mast cell growth and morphology.
• Immunohistochemistry and flow cytometry confirm mast cell markers (CD117, CD25, CD2).

Biopsy of skin

• Used for skin lesions.
• Imaging tests
• Check for organ enlargement or bone involvement by X-rays, CT scans, ultrasounds, or bone density tests.

Genetic testing

• KIT gene variants (particularly D816V) that promote mast cell growth.

Criteria for diagnosis

According to the WHO, diagnosis requires:

• Criteria: dense mast cell infiltrates in bone marrow or other organs, plus one minor condition.
• Consider three minor criteria: KIT mutation.
• Misshapen mast cells
• Mast cell CD25/CD2 expression
• High tryptase (>20 ng/mL)

Key Point

Diagnosis is complicated and involves exclusion. Haematologists, allergists, and pathologists collaborate.

Systemic mastocytosis therapy

The video is about the self care for systemic mastocytosis

Systemic mastocytosis (SM) treatment depends on severity, subtype, and organs. Limiting mast cell proliferation, severe allergic reactions, and symptoms are the key goals.

1. Managing Symptoms

• Antihistamines
• H1 blockers (itching, flushes, hives)
• For stomach acid, ulcers, and abdominal pain, H2 blockers
• Reduce inflammation and allergy symptoms with leukotriene inhibitors
• Some severe inflammation requires corticosteroids.
• Epinephrine auto-injectors for anaphylactic emergencies

2. Trigger Avoidance

• Avoid alcohol, NSAIDs, insect stings, and high-histamine meals that activate mast cells.
• Certain medicines can release mast cells; thus, careful control before surgery or anaesthesia is needed.

3. Targeted Treatments

• Tyrosine kinase inhibitors
• Advanced systemic mastocytosis is treated with midostaurin and avapritinib. They target mast cell proliferation-causing KIT mutations (typically D816V).
• Interferon-alpha or cladribine can lower mast cell load in aggressive situations.

4. Organ and Bone Support

• Bone pain/osteoporosis: bisphosphonates.
• Regular liver, spleen, and bone marrow monitoring.

5. Advanced SM

• Select aggressive varieties or those associated with hematologic neoplasms like leukemia that may be treated with chemotherapy-like drugs or stem cell transplantation.

Key Point

• Lazy SM: Manages symptoms and quality of life.
• Advanced SM: Some cytoreductive and targeted therapy are needed.

Conclusion

Systemic mastocytosis is a rare, chronic condition characterised by the accumulation of mast cells in multiple organs. Genetic changes in the KIT gene lead to the uncontrolled growth of mast cells, which causes too much histamine and other substances to be released.

Some systemic mastocytosis individuals have mild symptoms, while others have serious consequences. Early detection, individualised therapy, and continuing monitoring improve outcomes.