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constitutional symptoms

The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 3

I have answered the 107 questions I have been asked most in the last four years. No jargon. No terminology. Just answers.

6. What symptoms does mast cell disease cause?

  • Mast cell disease can cause just about any symptom. Seriously.
  • Mast cell disease can cause symptoms in every system of the body. This is because mast cells are found in tissues throughout the body. They are intimately involved in lots of normal functions of the human body. When mast cells are not working correctly, lots of normal functions are not carried out correctly. When this happens, it causes symptoms. In short, mast cells can cause symptoms anywhere in the body because they were there already to help your body work right.
  • Skin symptoms can include flushing, rashes, hives (urticaria), itching, blistering, and swelling under the skin (angioedema).
  • GI symptoms include nausea, vomiting, diarrhea, constipation, problems with the GI not moving correctly in general (GI dysmotility), swelling of the GI tract, chest and abdominal pain, belching, bloating, discolored stool, excessive salivation, dry mouth, and trouble swallowing.
  • Cardiovascular symptoms include high or low blood pressure, fast or slow heart rate, irregular heartbeat, and poor circulation.
  • Neuropsychiatric symptoms include brain fog, difficulty concentrating, difficulty sleeping at night, excessive tiredness during the day, grogginess, anxiety, depression, tremors, numbness, weakness, burning and tingling (pins and needles), hearing loss, and auditory processing (difficulty understanding what was said to you).
  • Genitourinary symptoms include bladder pain, painful urination, painful intercourse/sexual activities, painful or irregular menstrual cycle (periods), and excessive or inadequate urination (too much or too little urine produced).
  • Respiratory symptoms include cough, excessive phlegm, wheezing, runny nose, sinus congestion, sneezing, and swelling of the airway.
  • General symptoms include fatigue, lack of stamina, difficulty exercising, itchy or watery eyes, and bruising easily.
  • There are some additional symptoms that I have observed in a large number of people that are not classically considered mast cell symptoms, but I now firmly believe them to be. One is fever. I think discoloration of the skin may be mast cell related for some people. Another is dystonia, involuntary muscle contraction, which can mimic appearance of a seizure. There are also different seizure-type episodes that may occur due to the nervous system being overactive. I am reluctant to call them pseudoseizures because that term specifically means they are caused as a result of mental illness. I have no evidence that these seizure-type episodes in mast cell patients occur due to mental illness. I personally refer to them as “mast cell derived seizures.” (For people who are wondering, I have been heavily researching this phenomenon and have some theories about why this happens. It’s not fleshed out enough yet to post but it’s on my think list.)
  • Having mast cell disease can make you more likely to have other conditions that cause symptoms.
  • I’m sure there are other symptoms I have forgotten to mention.

7. Why are skin and GI symptoms so common?

  • The skin has a lot of mast cells relative to other tissues. Your skin also comes into contact with lots of things in the environment. Think about the things your skin touches on a daily basis! It makes sense that it would get the exposure so skin symptoms can be common. Additionally, some of the chemicals mast cells release can cause fluid to become trapped in the skin. For these reasons, symptoms affecting the skin are pretty common.
  • The GI tract also has a lot of mast cells relative to other tissues. Your GI tract also comes in contact with lots of things in the environment. Let’s think about this for a minute. Your GI tract is essentially one long tube through your body. You put things from the environment in your GI tract at the top and they come back out the bottom of the tract. In a way, your GI tract is kind of like the outside of the inside of your body.
  • This is the analogy I learned in anatomy and physiology class to visualizing the GI tract as the outside of the inside of the body. Think of the body as a donut. (A low histamine, fully allergy friendly, requires no GI motility, wonderful donut.) Now think of the GI tract as the donut hole. You can put your finger through the hole in the middle of the donut. Only that center part of the donut will touch your finger. This is kind of like putting food throughout the GI tract. That food only touches a very small part of the body as it passes through.
  • Since what we put into our mouths (or other GI openings) is from the outside, your body has many mast cells in the GI tract to protect the body. Some of the chemicals mast cells release can cause fluid to become trapped in the layers of GI tissue. Some of the medications we take for mast cell disease can affect the GI tract. Some of them change how much acid we make in our stomachs. Some of them slow down the GI tract. A few of them speed it up or make the GI tract more fragile. For these reasons, symptoms affecting the GI tract are very common.

For more detailed reading, please visit these posts:

The Provider Primer Series: Management of mast cell mediator symptoms and release

The Provider Primer Series: Mast cell activation syndrome (MCAS)

The Provider Primer Series: Cutaneous Mastocytosis/ Mastocytosis in the Skin

The Provider Primer Series: Diagnosis and natural history of systemic mastocytosis (ISM, SSM, ASM)

The Provider Primer Series: Diagnosis and natural history of systemic mastocytosis (SM-AHD, MCL, MCS)

Constitutional symptoms of MCAS

Constitutional symptoms are any symptoms that affect the function of several systems at once.  They are often nonspecific and can be attributed to many causes, complicating diagnosis. For many people with MCAS, the constitutional symptoms present first and with the greatest frequency.

Fatigue and malaise (the feeling of being “out of it”) are the most common symptoms reported in MCAS patients.  While many patients with these symptoms remain functional, for some, it can be truly, severely disabling, with some patients sleeping for the majority of the day.  Dr. Afrin has referred to stories of “patients in their twenties acting like they are in their eighties.”  Chronic fatigue syndrome, in which patients have severe fatigue unrelated to exertion, not relieved by rest and unrelated to other medical conditions, has been tentatively linked to mast cell activation by Dr. Theoharides. 

I see a lot of discussion about whether or not fevers are part of MCAS.  It depends which researcher is reporting information.  Castells feels strongly that fevers are not part of MCAS symptomology, while Afrin and Molderings feel that they are.  They report that intermittent elevated temperatures are not unusual.  These temperatures are low-grade temperatures, with frank fever being quite rare.  MCAS patients often report constantly feeling cold, though chills and shaking is less common.

I know that one of the ways I can tell my mast cell disease is ramping up is by severe night sweats.  This is apparently common in most presentations of mast cell disease.  As such, many MCAS patients have severe, unprovoked sweating, often overnight, sometimes not.  Some patients report a circadian rhythm.  Furthermore, this sweating is often accompanied by swollen or tender lymph nodes.  When these two symptoms are taken together, usually infection or lymphoma is suspected.  Once these are ruled out, patients are often left with no relief for this frustrating symptom.

Some patients report lack of desire to eat.  Some report quickly feeling full (early satiety.)  In some of these patients, the root cause is a swollen spleen.  A minority of MCAS patients lose weight due to their disease.

Weight gain in MCAS patients is far more common than weight loss.  It often begins suddenly and progresses rapidly, in the absence of dietary or activity changes.  This is partially due to the fluid dynamics of edema due to mast cell activation.  Less often, weight gain is from ascites (free fluid in the abdomen) or serositis, inflammation of the serous tissues, including the pleura (tissue lining the lungs), pericardium (the compartment containing the heart and origination of the large vessels connecting to the heart) and the peritoneum (tissue lining the abdomen.) 

However, the gain in adipose (fat) tissue seems to be responsible for most of the persistent weight gain.  Some patients gain more than 50kg in a year despite significant caloric restriction and frequent exercise.  Many people (and their providers) often attribute their worsening symptoms to the gained weight.  Some people undergo bariatric surgery and despite initial losses, regain the weight, with no improvement of other symptoms.

Pruritis (itching) is very common in MCAS.  Its presentation is varied; episodic or constant; local or diffuse; migratory or not; tolerable or disabling.   

The hallmark of MCAS is that patients invariably present with a collection of “sensitivities.”  These include severe or bizarre reactions to virtually anything, including drugs, food and environemental triggers.  Environmental triggers can be due to the presence of common allergens, physical (such as heat), electrical (such as generation of electrical charge when brushing hair) and even osmotic.  Exposure to harmless microorganisms can cause severe reactions.  Summers are often difficult for MCAS patients due to heat and increased UV exposure, while spring and fall are difficult due to pervasive pollen.  Triggers can cause reactions when the patient touches, inhales or ingests them. 

Though less of a problem than heat, exposure to cold can trigger a hyperadrenergic response that will fuel mast cell activation.  Care must be taken to avoid temperature extremes on either end of the spectrum.

Drug sensitivities are often found to be due to an inactive ingredient in the formulation.  Compounding is an important tool for MCAS patients.  Lactose monohydrate and potato are common fillers for MCAS patients.  Reconstitution at time of use with water is also not uncommon.



Afrin, Lawrence B.  Presentation, Diagnosis and Management of Mast Cell Activation Syndrome.  2013.  Mast Cells.