About Mast Cell Activation Syndrome • MCAS
By Kevin on
Name of the medical condition and other names that it’s been known by
Mast Cell Activation Syndrome
MCAS
Mast Cell Activation Disease
Mast Cell Activation Disorder
What is Mast Cell Activation Syndrome?
MCAS is a condition where mast cells—a vital part of your immune system—become hyper-reactive. Normally, these cells release mediators like histamine to help fight infections or heal injuries. In MCAS, they release these chemicals too easily and too often, even without a clear trigger. This can lead to multi-system symptoms and, in severe cases, life-threatening anaphylaxis.
The Three Primary Types
Primary MCAS: Occurs when mast cells clone themselves excessively, leading to an overabundance of cells in various organs.
Secondary MCAS: The mast cells are normal in number but overreact to external stimuli, such as pollen, food, or other allergens.
Idiopathic MCAS: Symptoms are present and meet diagnostic criteria, but doctors cannot identify a specific underlying cause or trigger.
Common Symptoms of MCAS
Symptoms can occur in various combinations and fluctuate in severity over time:
Skin: Itching (pruritus), flushing, hives (urticaria), sweating, swelling (angioedema), and rashes.
Eyes, Nose, & Mouth: Irritation, watering, itching, running nose, and swelling of the tongue, lips, or throat.
Lungs: Trouble breathing, wheezing, and shortness of breath.
Heart & Blood Vessels: Low blood pressure (hypotension), rapid pulse (tachycardia), and lightheadedness or fainting.
Stomach & Intestines: Cramping, nausea, vomiting, diarrhea, bloating, and difficulty swallowing.
Nervous System: Brain fog, headaches, fatigue, anxiety, depression, and sensitivity to light or sound.
Other: Bone pain, joint hypermobility, interstitial cystitis, and various metabolic or hormonal abnormalities.
How is it Diagnosed?
Diagnosis is often complex and involves several steps:
Symptom Recognition: Identifying chronic, recurrent symptoms affecting two or more organ systems.
Mediator Tests: Blood or urine tests (such as serum tryptase) to see if mast cells are releasing excessive chemicals.
Treatment Response: Observing if symptoms improve with medications that block mast cell chemicals.
Rule Out: Ensuring no other disease is causing the symptoms.
How is it Treated?
Management focuses on stabilizing mast cells and blocking the chemicals they release:
Avoid Triggers: Identifying and removing specific environmental or dietary triggers.
Antihistamines: Blocking the effects of histamine (H1 and H2 blockers).
Mast Cell Stabilizers: Medications that help prevent cells from releasing chemicals.
Leukotriene Inhibitors: Blocking other inflammatory chemicals involved in the response.
Emergency Care: Carrying an epinephrine auto-injector for anaphylaxis.
Trend
Prevalence: MCAS is currently considered rare, though it is frequently underdiagnosed or misidentified due to its complex nature.
Recent Activity: Awareness among the public and medical professionals has increased significantly over the last five years, leading to more frequent diagnoses.
Projections: As research clarifies diagnostic criteria, the number of confirmed cases is expected to rise over the next five years.
History
While mastocytosis (a condition of too many mast cells) has been known for decades, MCAS was only formally described in the early 2000s. Doctors noticed a subset of patients who exhibited all the symptoms of mast cell overactivity but had a normal number of cells in their bone marrow. This led to the recognition of MCAS as a distinct functional disorder of the immune system.
Mast Cell Activation Syndrome - Sources of Information
For informational purposes only. Consult a medical professional for advice.