MCAS
Unexplained abdominal pain, skin reactions, palpitations, exhaustion, food intolerances –
and no explanation? Mast Cell Activation Syndrome (MCAS) affects multiple organ systems simultaneously and is therefore often overlooked. I support you with my many years of expertise as one of the leading MCAS experts in Europe – internationally connected, scientifically active, and co-author of the book MCAS – The Hidden Disease.
“MCAS is complex – but it is treatable. Individually. With patience and a great deal of clinical sensitivity. The key is detecting the patterns.”
Dr. Katja Aschenbrenner. M.D.
Key Symptoms –
diverse, fluctuating, often diffuse
Because mast cells are distributed throughout the entire body – skin, gut, lungs, blood vessels, nervous system – symptoms can vary widely. Affected systems include usually:
Skin & mucous membranes:
Itching, hives (urticaria), flushing (sudden skin redness), angioedema, rashes, skin sensitivity
Gastrointestinal tract:
Abdominal cramps, bloating, diarrhea or constipation, nausea, reflux, food intolerances
Heart & circulation:
Palpitations, blood pressure instability, chest discomfort, dizziness; in severe cases shock or fainting
Respiratory system & lungs:
Asthma-like symptoms, shortness of breath, coughing, mucosal swelling
General & nervous system:
Fatigue, exhaustion, brain fog, concentration problems, sleep disturbances, mood swings; hypersensitivity, anxiety, panic attacks
Because MCAS presents in so many different ways, patients often see multiple specialists over many years without the underlying connection being recognized.
I am Dr.
Katja Aschenbrenner, M.D.
I am one of the
leading experts in Mast Cell Activation Syndrome (MCAS).
Through international collaborations, scientific networks, publications and my work as a book author, I combine deep clinical experience with the latest research. You can find my most recent publication in The American Journal of the Medical Sciences here.
Solution / Healing
A New Perspective
Step 1: Thorough medical history and symptom assessment
The process begins with a detailed medical history and comprehensive symptom assessment. Particular attention is paid to whether several organ systems are affected at the same time, as this is a typical hallmark of Mast Cell Activation Syndrome (MCAS).
Step 2: Exclusion of other conditions / differential diagnosis
Many symptoms of MCAS overlap with those of other medical conditions, such as allergies, gastrointestinal disorders, neurological diseases or immunological conditions. Before a diagnosis of MCAS can be made, other possible causes must therefore be carefully and systematically ruled out.
Step 3: Laboratory diagnostics – evidence of mast cell activation
A central component of the diagnostic process is laboratory testing for mast cell mediators. These are substances released by mast cells when they are activated and provide important evidence of mast cell dysregulation.
Step 4: Therapeutic trial and observation of response
Based on clinical suspicion and initial laboratory findings, a therapeutic trial may be initiated, for example with antihistamines or mast cell stabilizers. A clear improvement of symptoms under treatment is considered an additional criterion supporting the diagnosis of MCAS.
I understand you –
a patient shares her story:
“At some point, I no longer knew what my body would do next. One day I could eat a certain food without any problems, the next day I would react with heart palpitations, burning skin and abdominal cramps.
This constant guessing – combined with doctors who did not understand me – completely dominated my daily life. Only when I was diagnosed with MCAS did everything suddenly make sense.”
Patient, anonymous
What Treatment Looks Like
Step by Step
1. Initial consultation
2. Diagnostics & laboratory testing
3. Development of an individualized treatment plan
4. Ongoing counseling (nutrition, triggers, daily life)
5. Regular adjustments & follow-up monitoring
MCAS sounds non-specific – could it be something else?
This is a valid concern. That is why we place great importance on a careful medical history, thorough differential diagnostics and mediator testing in order to avoid misdiagnosis.
Who Is Treatment
Suitable For?
Suitable for people who:
- experience recurring, unexplained symptoms – especially involving multiple organ systems (e.g. skin + gastrointestinal, cardiovascular + fatigue)
- have suspected histamine intolerance with unclear cause or insufficient treatment response
- have ruled out classic allergies but symptoms persist or have become chronic
- seek thorough, holistic diagnostics and individualized care – with internationally recognized expertise
Less suitable for people who:
- expect a quick, standardized solution
MCAS requires individualized diagnostics and step-by-step treatment. Those looking for an immediate “miracle cure” are unlikely to be satisfied. - are unwilling to observe and adapt their lifestyle
Identifying triggers is a crucial part of treatment. Without active participation, therapy loses effectiveness. - accept only laboratory values as proof
MCAS cannot always be clearly measured. Insisting solely on “positive tests” can make the diagnostic process frustrating. - do not want long-term medical support
MCAS is chronic. Long-term collaboration is often necessary to achieve stability. - want their symptoms explained exclusively as psychological
We take symptoms seriously, work with a body-oriented, immunological approach.
Those seeking a purely psychosomatic explanation may not feel aligned here.
Is MCAS common?
Yes. According to current literature, MCAS may be significantly more common than previously assumed.
Afrin et al. estimate that up to 17% of the general population could be affected – making it far from a rare condition.
What exactly is Mast Cell Activation Syndrome (MCAS)?
MCAS is a chronic condition in which mast cells overreact and release excessive mediators such as histamine.
This leads to symptoms across multiple organ systems – most commonly the gut, skin, respiratory tract, circulation and nervous system.
Symptoms are often fluctuating and difficult to categorize.
How is MCAS different from histamine intolerance?
In histamine intolerance, the problem is usually impaired histamine breakdown.
In MCAS, mast cells themselves release excessive histamine and other mediators.
Although symptoms may overlap, causes and treatment strategies differ.
Can MCAS appear suddenly?
Yes.
Many patients report symptom onset or worsening after infections, hormonal changes, significant stress or strain.
MCAS may develop gradually or seemingly “out of the blue.”
Is MCAS curable?
MCAS is a chronic condition.
It is not curable, but very well treatable when individual triggers are identified and appropriate therapies are applied.
Many patients experience a significant improvement in quality of life.
Why is diagnosis so difficult?
Because symptoms are diverse and resemble many other conditions.
Additionally, many physicians are unfamiliar with MCAS.
Patients often experience a long diagnostic journey before receiving an appropriate diagnosis.
How quickly does treatment work?
This varies greatly.
Some patients notice improvement within days, others require weeks or months for stabilization.
A gradual approach and regular adjustments are essential.
Do I need to completely change my diet?
Not necessarily.
The goal is to identify individual triggers, not to prohibit everything.
Often, targeted adjustments or temporary relief phases are sufficient to achieve meaningful improvement.
Are my symptoms “psychological”?
No.
MCAS is a physical, immunological disease.
Stress can worsen symptoms but is not the cause.
Your symptoms are real and medically explainable.