Postural Orthostatic Tachycardia Syndrome

How to recognize and treat Mast Cell Activation Syndrome

Do you experience muscle pain? Do you have recurring bouts of wheezing, coughing, or shortness of breath? Or, do you feel your heart beating rapidly, suffer from headaches, confusion – even anxiety or depression? If these symptoms are familiar to you, you may have Mast Cell Activation Syndrome (MCAS).

What are mast cells, and what is MCAS?

Mast cells, when functioning normally, release chemical mediators that help our bodies resist infection and repair damaged tissue. Mast cells are our first line of defense; when we are exposed to a perceived threat, it is our mast cells’ job to neutralize the threat.  

When you suffer from Mast Cell Activation Syndrome, your mast cells become confused. Instead of releasing chemical mediators to deal with real threats to your body and immune system, mast cells release mediators in response to harmless substances or stimuli. This inappropriate release of mediators can negatively affect many different systems in your body and is usually chronic.

The onset of MCAS is often unpredictable and abrupt. Triggers include excessive heat or cold, stress, exercise, alcohol consumption, insect bites, antibiotics, pollen, and pollution. Even things as benign as sunlight or perfume can trigger Mast Cell Activation Syndrome.

How do I know if I have MCAS?

Mast Cell Activation Syndrome patients will notice a variety of symptoms, some of which are unpleasant but manageable, and others which are immobilizing and resistant to treatment. You can experience depression, anxiety, and mild or severe fatigue when MCAS affects your brain. When mast cells activate in your GI tract, you may feel nausea, diarrhea, and vomiting. Other symptoms include an increased or rapid heart rate, muscle pain, and flushing in the face, neck, and chest.  When MCAS affects your skin, you can suffer from hives, itching in your nose or throat, rashes, and inflammation. Blood work is needed for diagnosis (and to rule out other causes of similar symptoms).

How we deal with Mast Cell Activation Syndrome

At POTS Care, we first need to determine if your symptoms are truly due to mast cell activation. Numerous conditions can mimic mast cell activation but need to be identified to properly treat the patient. If these are not identified the patient can be left to suffer, but they often assume (sadly) there is nothing else to be done. We are careful to analyze inflammation (even down to the genes involved!) to properly diagnose this condition and those that present similarly to mast cell activation.

Many inflammatory cells release similar chemicals as mast cells (such as histamine or prostaglandins). Eosinophils, for example, have been linked to POTS and must be identified properly. Additional inflammatory cells can also mimic MCAS — and often one inflammatory cell calls in other inflammatory cells. Rarely is one type of inflammatory cell the only problem that needs to be addressed. If mast cells are activated, blood levels of tryptase will rise when a patient is symptomatic. Confusing the picture, however, is that genetic disorders (perhaps unrelated to mast cells) can also cause a rise in tryptase! A close analysis of blood work, patient presentation, and genes (when possible) will provide us with the complete picture.

Finally, if your mast cells are activated we then ask, “What has activated them?” Until we understand what has worsened the patient, we risk treating only the symptoms, where treating the source of the activation can be much more beneficial. 

This is tricky to accomplish and every patient must be evaluated and treated as an individual. To do so, we toss out labels and evaluate POTS and comorbid conditions from their onset. If you’ve ever wanted a team to dig deeply into your case to locate and treat your issues at the source, you have found that team at POTS Care.

References available below.

A word from our Clinical Director, Diana Driscoll, OD

“I first became interested in mast cell problems because as an eye doctor, I treat mast cell involvement of the eye routinely. It wasn’t until I was misdiagnosed as an MCAS patient that I was forced to dig deeper.”

POTS Care is the only clinic devoted to treating the underlying medical cause of Idiopathic POTS – not just the symptoms. 

Call our patient care coordinator today to discuss treatment options. 1-(866)-DIZZY-05 or 1-(866)-349-9905


Krystel-Whittemore, M., Dileepan, K. N., & Wood, J. G. (2016). Mast cell: a multi-functional master cell. Frontiers in immunology, 6, 620.

Haenisch, B., Nöthen, M. M., & Molderings, G. J. (2012). Systemic mast cell activation disease: the role of molecular genetic alterations in pathogenesis, heritability and diagnostics. Immunology, 137(3), 197-205.

Hannah-Shmouni, F., Stratakis, C. A., & Koch, C. A. (2016). Flushing in (neuro) endocrinology. Reviews in Endocrine and Metabolic Disorders, 17(3), 373-380.

Izikson, L., English III, J. C., & Zirwas, M. J. (2006). The flushing patient: differential diagnosis, workup, and treatment. Journal of the American Academy of Dermatology, 55(2), 193-208.

Huang, K, Dellon E (2019). Increased Prevalence of Autonomic Dysfunction due to Postural Orthostatic Tachycardia Syndrome in Patients with Eosinophilic Gastrointestinal Disorders. J Gastrointestin Liver Dis, 28(1), 47-51.