A health condition that causes multiple and intense episodes of swelling, dyspnea (shortness of breath), hives, diarrhea, vomiting, and other symptoms is called mast cell activation syndrome (MCAS). In more severe cases, people with MCAS may experience anaphylaxis. This condition happens due to mast cells that mistakenly alert the immune system that something harmful is in the body.
Generally, mast cells are a type of immune cell that is responsible for immune reactions. For example, health conditions (such as allergic rhinitis, asthma, and others), allergic reactions (such as anaphylaxis to drugs or food), and mastocytosis all activate mast cells. As a result, the affected person begins to experience symptoms. Moreover, there are other common diseases that can cause unexplained symptoms. It is very important to inform your physician about any concerns.
However, MCAS occurs rarely, and doctors diagnose it based on the following factors. For example:
- Recurrent symptoms of possible anaphylaxis without a clear trigger
- The condition affects multiple systems in the body at the same time
- Tests show signs of mast cell activation
- You take medicines for MCAS, and the symptoms improve
Mast Cells Function
These cells are a part of the immune system responsible for protecting the body from germs (such as parasites, bacteria, viruses, and others). Mast cells are found in the body tissues. When they identify something harmful, they release histamine and other chemicals that activate your immune system.
Symptoms
Usually, people with MCAS experience the following symptoms. Examples include:
- Flushing (including hot, red, or pink skin)
- Itchy skin
- Hives
- Nasal congestion
- Swelling of the lips, eyes, tongue, face, or throat (also known as angioedema)
- Constipation or diarrhea
- Hypotension (low blood pressure)
- Belly (abdominal) pain
- Vomiting
- Dyspnea
- Weakness
- Fainting
- Anaphylaxis (this is a severe allergic reaction that may cause a combination of the previous symptoms)
Currently, it is known that MCAS affects multiple systems of the body. For example:
- Cardiovascular system (including heart and blood vessels)
- Digestive system (including GI tract)
- Respiratory system (including lungs and airways)
- Skin
Causes and Triggers
Normally, mast cells react when potentially harmful substances enter the body. Hence, these immune cells begin to release proteins and specific chemicals to fight the invaders. However, in people with MCAS, they react when they should not. Moreover, this condition does not seem to have a clear trigger that causes the symptoms. Nowadays, no one knows the exact cause of this condition.
While there are a lot of things that can trigger mast cells to release histamine, MCAS can be triggered unpredictably and by anything specific. Sometimes, people experience the symptoms more frequently due to changes in their life or environment, including periods of high stress or shifting weather. However, if you experience symptoms after something specific, it is less likely that you have MCAS.
What Are The Possible Complications of Mast Cell Activation Syndrome?
People who develop this condition may also experience some complications, especially if they leave it untreated. Check some examples below:
- Anaphylaxis – This is one of the most severe complications of MCAS because it causes severe airway, skin, or cardiovascular reactions.
- Tachycardia (fast heart rate)
- Dizziness
- Fainting (syncope)
- Hypotension (low blood pressure)
- Chronic pain
- Urticaria
- Dyspnea
- Mental health problems
The previous list does not contain a complete list of MCAS complications. In any case, you can talk with your doctor about ways to reduce the risk or even prevent them.
Diagnosis
Usually, doctors diagnose this syndrome based on a physical examination, symptoms, and medical history. However, they may also perform some tests to confirm or rule out MCAS. For example:
- Blood tests – These tests are performed multiple times to check for the levels of Tryptase (a substance present in people with MCAS). It is important to know that Tryptase levels may also increase due to other health conditions. Sometimes, people have high Tryptase levels naturally, and they do not have any symptoms.
- Allergy skin test – This test is often done to exclude other health conditions that cause similar symptoms.
Treatment
Doctors often prescribe treatment to reduce the symptoms, prevent life-threatening complications, and improve your quality of life. Moreover, if you do not notice improvements with MCAS medicines, you may not have this condition. Check some options often recommended by doctors below:
- Histamine type 1 and type 2 receptor blockers (antihistamines) – Doctors often recommend Loratadine, Cetirizine, Ranitidine, Famotidine, or Fexofenadine to reduce nausea and vomiting.
- Aspirin – This medicine can reduce flushing.
- Leukotriene modifiers – These medications are used to improve breathing. Doctors often recommend Zafirlukast and Montelukast.
- Omalizumab – This medicine is used to reduce anaphylactic episodes.
- Epinephrine – Doctors often recommend this medication to stop anaphylaxis. You should carry an Epinephrine injector with you, especially if you have had anaphylactic episodes.
- Mast cell stabilizers – Your doctor may prescribe Cromolyn sodium to prevent mast cells from releasing mediators.
- Corticosteroids – This group of medications is used to reduce inflammation, which helps open airways and reduce fluid in tissues. However, these medicines should not be used for long periods because they can cause severe adverse reactions.
Frequently Asked Questions
Does MCAS go away on its own?
Unfortunately, there is no way to cure this syndrome, and most people with this syndrome administer medicines for the rest of their lives.
What is the life expectancy of someone with mast cell activation syndrome?
In general, this condition does not affect lifespan. It means a person with MCAS often lives as long as someone without it.
What does a mast cell flare feel like?
The activation of mast cells feels like an allergic reaction. However, for people with MCAS, episodes are more severe than an allergic reaction and involve multiple parts of the body. For instance, you may experience swollen and red skin, hives, dyspnea, vomiting, diarrhea, and other symptoms.
When should I go to the ER?
People who develop the following symptoms should immediately call 911 or go to the nearest emergency room (ER). For example:
- Breathing or swallowing problems
- Loss of consciousness
- Hypotension
- Swollen face, lips, tongue, or throat
If you have any other questions, ask your healthcare provider.
