Summary about Disease
Mastocytosis is a rare disorder characterized by an abnormal accumulation of mast cells in one or more tissues of the body. Mast cells are part of the immune system and release substances that cause inflammation and allergic reactions. The symptoms and severity of mastocytosis can vary greatly, ranging from mild skin involvement (cutaneous mastocytosis) to systemic involvement affecting multiple organs.
Symptoms
Symptoms vary depending on the type of mastocytosis and which organs are affected. Common symptoms include:
Skin: Hives (urticaria), itching, flushing, Darier's sign (skin blistering or swelling when rubbed), maculopapular rash (urticaria pigmentosa)
Gastrointestinal: Abdominal pain, nausea, vomiting, diarrhea, bloating
Cardiovascular: Lightheadedness, dizziness, rapid heartbeat (tachycardia), low blood pressure (hypotension)
Respiratory: Wheezing, shortness of breath
Neurological: Headaches, fatigue, cognitive dysfunction ("brain fog")
Skeletal: Bone pain, osteoporosis
Systemic: Anaphylaxis (severe allergic reaction)
Causes
Mastocytosis is primarily caused by genetic mutations that affect the KIT gene. The KIT gene provides instructions for making a protein called KIT, which is a receptor tyrosine kinase. This protein is important for the growth, development, and survival of mast cells. Mutations in the KIT gene can cause mast cells to proliferate uncontrollably and accumulate in tissues. While some cases are inherited, most are thought to arise from spontaneous mutations.
Medicine Used
Treatment focuses on managing symptoms and preventing mast cell activation. Medications may include:
Antihistamines: To block the effects of histamine released by mast cells.
Cromolyn sodium: Stabilizes mast cells and prevents the release of inflammatory substances.
Leukotriene inhibitors: Block the action of leukotrienes, another type of inflammatory mediator.
Proton pump inhibitors (PPIs) or H2 blockers: To reduce stomach acid production and alleviate gastrointestinal symptoms.
Epinephrine: For emergency treatment of anaphylaxis.
Corticosteroids: To reduce inflammation. Used cautiously due to side effects.
Omalizumab: A monoclonal antibody that blocks IgE, potentially reducing mast cell activation in some patients.
KIT inhibitors (e.g., midostaurin, avapritinib): For advanced systemic mastocytosis; target the mutated KIT protein.
Bisphosphonates: To treat bone loss and osteoporosis.
Phototherapy (PUVA or UVB): For skin symptoms.
Is Communicable
No, mastocytosis is not communicable. It is not contagious and cannot be spread from person to person.
Precautions
Precautions are aimed at avoiding triggers that can activate mast cells and cause symptoms:
Avoid known allergens: Food, medications, insect stings, etc.
Avoid extreme temperatures: Sudden changes in temperature can trigger mast cell activation.
Avoid certain medications: Nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and some anesthetics can trigger mast cell reactions. Consult with a doctor before taking any new medication.
Avoid physical triggers: Rubbing, scratching, or pressure on the skin.
Carry an epinephrine auto-injector: If at risk for anaphylaxis.
Wear medical alert identification: To inform healthcare providers about the condition in case of emergency.
Stress management: Stress can trigger mast cell activation, so techniques like meditation or yoga can be helpful.
How long does an outbreak last?
The duration of symptoms and outbreaks varies greatly depending on the type and severity of mastocytosis. Some individuals may experience only intermittent symptoms triggered by specific factors, while others may have persistent symptoms that wax and wane over time. Anaphylactic reactions are acute and require immediate treatment. Skin lesions may persist for weeks or months. Chronic symptoms can last for years.
How is it diagnosed?
Diagnosis typically involves a combination of the following:
Medical history and physical examination: To assess symptoms and identify potential triggers.
Skin biopsy: To examine skin tissue for increased numbers of mast cells.
Bone marrow biopsy: To assess mast cell infiltration in the bone marrow, especially in systemic mastocytosis.
Blood tests: To measure mast cell mediators such as tryptase. Elevated tryptase levels can suggest increased mast cell activity.
Urine tests: To measure mast cell mediators such as histamine metabolites.
Genetic testing: To identify KIT mutations.
Bone density scan (DEXA scan): To assess bone density and detect osteoporosis.
Gastrointestinal endoscopy with biopsies: To evaluate gastrointestinal involvement.
Timeline of Symptoms
The timeline of symptoms varies considerably.
Childhood-onset cutaneous mastocytosis: Often presents in infancy or early childhood with skin lesions. Symptoms may improve or resolve by adolescence in some cases.
Adult-onset mastocytosis: Can present at any age. Systemic mastocytosis tends to be more common in adults.
Acute episodes: Anaphylactic reactions can occur suddenly and require immediate treatment.
Chronic symptoms: Fatigue, bone pain, gastrointestinal issues, and cognitive dysfunction can persist for months or years.
Progressive disease: In some cases, particularly advanced systemic mastocytosis, the disease can progress over time with worsening symptoms and organ involvement.
Important Considerations
Individualized treatment: Management should be tailored to the specific symptoms and disease severity of each individual.
Multidisciplinary care: A team of specialists, including dermatologists, allergists/immunologists, hematologists, gastroenterologists, and other specialists, may be needed.
Patient education: Understanding the disease and how to manage it is crucial.
Emergency preparedness: Patients at risk for anaphylaxis should carry epinephrine auto-injectors and have an emergency action plan.
Long-term monitoring: Regular follow-up appointments are important to monitor disease progression and adjust treatment as needed.
Psychological support: Chronic illness can have a significant impact on mental health. Support groups and counseling can be helpful.
Research: Ongoing research is focused on developing new and more effective treatments for mastocytosis.