The MastAttack 107: The Layperson’s Guide to Mast Cell Diseases, Part 17

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

25. How do I know what I will react to?
There is no way to definitively know what things will make you react. It is difficult to predict. There are some general guidelines many of us use to figure out what may be a problem but the only way to really know is to try something.
• Please note that because mast cell reactions are not known to be triggered by the same mechanisms as traditional allergies, you cannot exclude an entire class of drugs because you react to one in the way that you do for traditional allergies. This is particularly worth noting for opiates: reaction to morphine, for example, does not exclude fentanyl or hydromorphone.
• Mast cell reactions are not inherently triggered by IgE the way that “true” allergies are. This means that blood tests for IgE allergies will not identify triggers accurately for most mast cell patients. (Although some mast cell patients do have some IgE allergies.)
• Additionally, skin testing is wildly inaccurate in mast cell patients because of how reactive our skin is.
Stopping antihistamines is dangerous for mast cell patients.
Allergy testing is not accurate for mast cell patients.
• There are several ways that various things can cause mast cell reactions. Generally, they do it in one of the following ways: they cause mast cells to empty the chemicals in their pockets into the body (degranulation); they cause mast cells to release chemicals in another way; they already contain significant amounts of histamine; or the interfere with the mechanisms for controlling mast cell activation.
There are a number of medications that can cause mast cell degranulation or histamine release. Please note that not all of these medications are problematic for every patient. Only a provider managing your case can determine if these are safe for you or not. The major medications that may cause degranulation or histamine are listed below. This list is not exhaustive.

-Alcohol: Widely used to sterilize body area, surfaces, or tools; also used when preparing many medications that are not soluble in water
-Amphoterecin: Antifungal
-Aspirin: NSAID, for pain, inflammation, to block prostaglandins, to prevent clot formation
-Atracurium, mivacurium, rocuronium: Muscle relaxant
-Caine anesthetics (esters): Anesthetics, to numb
-Codeine, morphine, meperidine: Opiates, for pain or cough
-Colistin: Antibiotic
-Dextran: Volume expander, used in surgical or emergency situations to improve blood pressure
-Dextromethorphan: Cough suppressant
-Miconazole: Antifungal
-Nefopam: For pain
-NSAIDs (non steroidal anti-inflammatory drugs): For pain, inflammation, blocking production of prostaglandin
-Polymyxin B: Antibiotic
-Radioopaque contrast: To visualize structures in medical scanning procedures
-Reserpine: High blood pressure medication and antipsychotic
-Succinylcholine: Paralytic used for surgical procedures
-Thiopental: Anesthesia induction for surgical procedures
-Vancomycin (especially IV): Antibiotic

• There are a number of medications that are known to interfere with the mechanisms for controlling mast cell activation. Adrenaline is naturally made by the body to help control mast cell activation and other activities. When you interfere with the ability of adrenaline to act, it can potentially trigger mast cell activation. Drug classes that do this include beta blockers and alpha adrenergic blockers. This is particularly an issue if there is a history of anaphylaxis because these medications can interfere with Epipens.
Many foods either contain histamine or can trigger mast cell release of histamine. As with medication, you cannot exclude an entire family of foods because you react to one in the way that you do for traditional allergies.
• There are many lists of foods to avoid. They often conflict with each other. There is not yet a definitive list available. Despite this, there are some general rules of thumb that are agreed upon on what to avoid.
• Products that are fermented, contain alcohol, are overly ripe or leftover from previous days (especially meats), or contain dyes or preservatives are generally excluded.
• Beyond this, recommendations vary a lot more. Many diets recommend excluding yeast, citrus fruits, and nightshade vegetables.
Many activities inherently activate mast cells. Being too hot, standing or sitting in direct sunlight, exercise, sexual activities, menstruation, infection, and any type of physical trauma, even minor, can trigger mast cell activation as part of normal mast cell function.
Premedication is recommended for any medical procedure, even minor, as they can trigger mast cell activation.
• Patients may find that premedication prior to other activating activities is helpful for suppressing reactions.
Ultimately, the only way to know what is activating is through trial and error. Patients should consult their care team about what to trial, when, and how to make it as safe as possible.

For more detailed reading, please visit these posts:

Food allergy series: Mast cell reactions and the low histamine diet

The Provider Primer Series: Introduction to Mast Cells

The Provider Primer Series: Medications that impact degranulation and anaphylaxis

The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 11

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

19. How do other conditions affect mast cell disease?
Mast cell activity can affect literally every system in the body.
• Mast cells are found throughout the body and live in many tissues and organs in significant numbers.
• There are essentially three types of damaging mast cell activity:
Normal mast cells are getting bad signals from other cells and they do bad things. This is not mast cell disease because these mast cells are not broken. They are getting signals from other broken cells.
Abnormal mast cells do bad things and tell other nearby cells to do bad things. This is mast cell disease, specifically mast cell activation syndrome and sometimes monoclonal mast cell activation syndrome.
You make way too many mast cells, they are abnormal, they do bad things, and they tell other nearby cells to do bad things. This is mast cell disease, specifically all forms of mastocytosis (systemic, cutaneous, and mast cell leukemia), sometimes monoclonal mast cell activation syndrome and mast cell tumors (mastocytoma and mast cell sarcoma).
• Generally speaking, if you have mast cell disease, any other condition you have will irritate your mast cell disease. This can also work the other way around and mast cell disease can irritate your other conditions.
• Many conditions naturally trigger higher level mast cell activation.
• Any disease that causes your body to make a lot of cells very quickly is likely to trigger to mast cell activation. Cancers are mast cell activating. Non cancerous diseases where you make too many blood cells at once, like polycythemia vera or essential thrombocythemia, are are mast cell activating.
• Mast cells are usually found very close to tumors. Sometimes, they are found inside tumors. Mast cells are important for tumors to survive because they can make blood vessels to bring tumors the blood they need.
Diseases affecting the immune system are triggering to mast cells. In fact, many patients have mast cell activation syndrome caused by the immune disease irritating their mast cells so much. Many mast cell patients have autoimmune diseases like lupus or rheumatoid arthritis. Many patients also have deficiencies in their immune system. Because mast cells are immune cells, they are very responsive to signals from other immune cells. Mast cells think those cells need help from them to fight an infection or disease so they respond strongly to “help”.
Diseases that cause inflammation also trigger mast cells. This can happen whether the inflammation is local or not. Systemic inflammation is more irritating to mast cells since that kind of inflammation can find more mast cells throughout the body. Local inflammation can irritate mast cells nearby. It can also call mast cells from other parts of the body to that location.
• Mast cells are actively involved in fighting infections from viruses, bacteria, fungi, and parasites. This is the reason many mast cell patients find they are more reactive when they have even a minor illness, like a cold.
Any type of physical stress can activate mast cells. This can be something as simple as exercise or something more traumatic such as a car accident, a surgery, or childbirth. Even things that should be easy to recover from can activate mast cells, like a small cut, dehydration, or getting overheated. This also includes stress caused by another disease.
Emotional stress can activate mast cells, even if the big emotion is joy.
For more detailed reading, please visit this page:

Symptoms and effects of mast cell disease


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)

The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 1

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

  1. What are mast cells?
    • Mast cells are white blood cells that live in tissues. It is a little misleading that mast cells are white blood cells because they don’t live in the blood. Mast cells are born in the bone marrow, the squishy tissue inside bones where blood cells are made. From the bone marrow, they are sent to the blood stream. Mast cells use the bloodstream to carry them to their final destination so they do not stay in the blood for very long. Mast cells move out of the blood stream and into tissues throughout the body. Mast cells live for months or years, a long time for cells to live in the human body.
    • Mast cells do many things in the body. They are largely responsible for allergic reactions and anaphylaxis. They have many other jobs, like healing wounds, regulating reproductive activities (menstruation, pregnancy), and fighting infections from viruses, bacteria, fungi, and even intestinal parasites like worms. The original function of mast cells thousands of years ago was probably to fight off intestinal parasites. Mast cells are found in many tissues and are essential for correct functioning of the body.
    • Mast cells have many pouches inside of them called granules. These granules hold chemicals made by the mast cells. These chemicals help the mast cells to do their various jobs. They also help mast cells to communicate with other cells nearby or in other parts of the body. These chemicals can be released into the bloodstream to signal for other immune cells to come to the mast cell that released them.
  2. What is mast cell disease?
    • Mast cell diseases are rare diseases in which your body makes too many mast cells and/or mast cells do not function correctly. In the US, diseases that affect fewer than 200,000 people are called rare diseases.
    • Mast cell diseases are broadly classified into two groups: clonal and non-clonal (also called proliferative and non-proliferative).
    • When the body makes too many copies of a broken cell, those cells are called ‘clonal’ cells. In clonal forms of mast cell disease, the bone marrow makes too many mast cells. Those mast cells also don’t work correctly. They use too much energy on the wrong things. Because these mast cells are often busy making truble, they don’t have as much energy to do their normal necessary functions.
    • Clonal mast cell diseases include all forms of systemic mastocytosis (indolent, smoldering, aggressive, and mast cell leukemia); all forms of cutaneous mastocytosis (urticaria pigmentosa, of which telangiectasia macularis eruptiva perstans is a subtype, diffuse cutaneous mastocytosis); mastocytoma (usually found on the skin but also found elsewhere); mast cell sarcoma; and monoclonal mast cell activation syndrome. Importantly, in clonal mast cell diseases, the problem is not just that too many mast cells are made – those mast cells must also be dysfunctional for the disease to be clonal.
    • In non-clonal mast cell disease, the number of mast cells may be normal, but the cells are broken. Importantly, people with non-clonal mast cell disease may make more mast cells than normal, but not enough to be considered a clonal disease. In these diseases, even if the bone marrow makes the normal amount of mast cells, they still do not work correctly. They use too much energy on the wrong things. Because these mast cells are often working to inflame the body when it is not needed, they don’t have as much energy to do their normal necessary functions.
    • Non-clonal mast cell diseases include all other forms of mast cell disease: mast cell activation syndrome (secondary and idiopathic); familial hypertryptasemia; and mastocytic enterocolitis, which is recognized by some groups as its own disease, and by other groups as part of different mast cell diseases.
    • In these diseases, mast cells do not function properly. In all mast cell diseases, mast cells can get irritated easily. They respond to things in the environment and inside the body that they think are dangerous, even when those things are normal and safe for most people. This response is called mast cell activation.
    • Mast cell activation causes many symptoms. Many of these symptoms are “allergic” in nature. Some are not directly recognizable as “allergic”. Symptoms can affect every bodily system or may be localized to only one or two. It differs from person to person and can change over time within a person. You cannot know which mast cell disease a person has based upon their symptoms.

For more detailed reading, please visit these posts:

The Provider Primer Series: Introduction to Mast Cells

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)

The Provider Primers Series: Introduction to Mast Cells

Mast cells : Introduction

  • Mast cells are bone marrow derived. They migrate to tissues before maturity and remain tissue bound.[i]
  • Mast cell development in tissues is regulated by a number of molecules, most significantly stem cell factor (SCF) which binds at the CKIT (CD117) receptor. A number of other molecules, including IL-3, IL-4 and IL-10, also participate in this process.[ii]
  • Mast cells are long lived, with some living for years in tissue.[ii]
  • Mast cells are versatile actors. Their functions and granule contents are tailored to the needs of the local microenvironment.[iii]
  • Mast cells perform a number of critical roles, including immune defense against microbes and larger parasites; clotting; wound repair; tissue remodeling; angiogenesis; regulation of reproductive cycle; digestion and GI motility; pain response; participation in stress response via interaction with HPA axis; inflammatory response; and regulation of sleep and some aspects of cognition.[iv]
  • Mast cells produce a multitude of mediators which are stored in granules or produced de novo. Stored mediators of consequence include histamine; tryptase; heparin; bradykinin; serotonin; and substance P. De novo mediators include prostaglandin D2; leukotrienes C4, D4, and E4; platelet activating factor; tumor necrosis factor; interferons; and a number of interleukins, including IL-1a, IL-1b and IL-6, among many others. [iii]

Mast cell involvement in disease

  • Mast cells are involved in the pathology of many conditions, including asthma[iv]; autoimmune diseases[iv]; GI dysmotility, including post-operative ileus[v]; cardiovascular events[iv], such as myocardial infarction, rupture of atherosclerotic plaques or aneurysms, and coronary syndromes, including Kounis syndrome[vi]; cardiovascular disease; malignant and neoplastic [iv]; chronic kidney disease[iv]; cutaneous conditions[iv], including many forms of urticaria; depression and anxiety; and chronic pain[vii].
  • Mast cells are effectors in all mast cell diseases.
  • Most famously, mast cells are involved in allergy and anaphylaxis.[viii]

Mechanisms of mast cell activation

  • Mast cells are primarily activated via IgE crosslinking at the FcεRI receptor. This is the mechanism for the classic allergy model in which specific IgE binds the target allergen and crosslinks at the FcεRI receptor on the surface of mast cells and basophils. In this traditional model, crosslinking causes immediate degranulation of stored mediators and late phase release of mediators produced de novo upon activation[viii].
  • There are several other mechanisms for direct mast cell activation that are independent of IgE.
  • A number of inflammatory molecules can directly activate mast cells by binding surface receptors including corticotropin releasing hormone; substance P; histamine; cysteinyl leukotrienes; adenosine; stem cell factor; IL-3; IL-4; IL-9; and IL-33, among others[ix].
  • Substances associated with immune defense and infection can directly activate mast cells. Products derived from pathogens can activate via toll like receptors (TLR2 and TLR4), Dectin-1 or CD48. Host production of β-defensins and complement C3a and C5a can also provoke mast cell activation[ix].
  • IgG can bind at FcγR receptors on mast cell surfaces. Immunoglobulin free light chains have triggered degranulation in murine models but this has not yet been demonstrated in humans[ix].

Definition of anaphylaxis

  • The definition of anaphylaxis continues to be disputed. The 2006 NIAID/FAAN criteria detailed below have been validated and are widely used.[x]
  • Anaphylaxis is likely when any one of the following three criteria is met:
  • Criterion 1: Acute onset of illness with skin and mucosal issue involvement (hives, itching, flushing, swelling of lips/tongue/uvula) with at least one of the following: compromised airway (difficulty breathing, wheezing, low blood oxygenation); or reduced blood pressure or symptoms thereof (fainting, incontinence.)
  • Criterion 2: Two or more of the following occurring after exposure to a likely allergen: skin or mucosal tissue involvement (hives, itching, flushing, swollen lips/tongue/uvula), compromised airway (difficulty breathing, wheezing, low blood oxygenation); reduced blood pressure or symptoms thereof (fainting, incontinence); or persistent GI symptoms (cramping, abdominal pain, vomiting).
  • Criterion 3: Reduced blood pressure after exposure to known allergen.  For adults, this is <90 mm Hg systolic, or at least 30% decrease from baseline.  For children under 1 year of age, this is <70 mm Hg systolic; ages 11-17, <90 mm Hg systolic.  For children 1-10 years of age, this is <(70 mm Hg + (2x age)).  So for a child who is 8 years old, this would be <(70 + (2 x 8)) = <86 mm Hg.


[i] Dahlin JS, Hallgren J. (2015). Mast cell progenitors: origin, development and migration to tissues. Molecular Immunology 63, 9-17.

[ii] Amin K. (2012). The role of mast cells in allergic inflammation. Respiratory Medicine, 106, 9-14.

[iii] Theoharides TC, et al. (2012). Mast cells and inflammation. Biochimica et Biophysica Acta (BBA) – Molecular Basis of Disease, 1822(1), 21-33.

[iv] Rao KN, Brown MA. (2008). Mast cells: multifaceted immune cells with diverse roles in health and disease. Ann NY Acad Sci, 1143, 83-104.

[v] De Winter, BY. (2012). Intestinal mast cells in gut inflammation and motility disturbances. Biochimica et Biophysica Acta, 1822, 66-73.

[vi] Kounis NG. (2016). Kounis syndrome: an update on epidemiology, pathogenesis, diagnosis and therapeutic management. Clin Chem Lab Med, 54(10), 1545-1559.

[vii] Chatterjea D, Martinov T. (2015). Mast cells: versatile gatekeepers of pain. Mol Immunol, 63(1), 38-44.

[viii] Galli SJ, Tsai M. (2013). IgE and mast cells in allergic disease. Nat Med, 18(5), 693-704.

[ix] Yu Y, et al. (2016). Non-IgE mediated mast cell activation. European Journal of Pharmacology 778, 33-43.

[x] Sampson HA, et al. (2006). Second symposium on the definition and management of anaphylaxis: summary report—Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium. J Allergy Clin Immunol, 117(2), 391-397.

Take home points: July 2015

Mast cell interactions with B and T cells
• Mast cells communicate with other cells by:
o Releasing chemicals to tell another cell to do something
o Other cells releasing chemicals to tell mast cells to do something
o Moving right up against other cells, which allows the cells to “talk”
• B cells are white blood cells that make antibodies and protect against infections.
o Mast cells can tell B cells to make IgE, an allergy antibody.
o When mast cells touch B cells, the mast cells can release IL-6 which tells B cells to live longer.
o Mast cells can tell B cells to make IgA, an antibody.
• T cells are white blood cells that have many functions.
o T cells and mast cells are found close together in many inflammatory conditions, like ulcerative colitis.
o Activated T cells can activate mast cells.
o Mast cells can tell T cells to proliferate and produce inflammatory molecules.
o A kind of T cell called Treg (T reg, like in regulatory) cells can make mast cells harder to activate and interfere with degranulation.

Mast cells in kidney disease
• Kidney disease is often not identified until 60-70% of functional kidney cells have been damaged beyond repair.
• Mast cells are rare in healthy kidneys.
o Damaged kidneys can have up to 60x the normal amount of mast cells.
o Mast cell count is not related to disease severity.
• Atopic disease, like atopic dermatitis and allergic asthma, is linked to idiopathic nephrotic disease, kidney disease of unknown origin.
o The nephrotic disease and atopic disease could be manifestations of the same overarching condition.
o In patients with both, IgE levels are high.
• Tryptase is elevated in some patients with kidney damage.
• Mast cells are responsible for bringing other inflammatory cells to the damaged kidney.
• Mast cells can cause fibrosis in kidneys.
• In some roles, mast cells can protect kidneys from damage.

Regulation of mast cells by IgE and stem cell factor (SCF)
• Mast cells are mostly regulated in two ways
• IgE binds to the IgE receptor (FceRI) on mast cells and activates them
o Activation by IgE results in degranulation and secretion of mediators
o IgE induces mediator release by affecting the amount of calcium inside mast cells
• Stem cell factor (SCF) binds to the CKIT receptor on mast cells and tells them to stay alive
o SCF also increases degranulation and production of cytokines
o SCF helps mast cells to adhere to other cells

Mast cells in vascular disease: Part 3
• Mast cells are involved in the formation and growth of aneurysms
• Activated mast cell populations are increased in vessels that rupture
• Chymase, a mast cell mediator, can degrade vessels and increase risk of rupture
• Leukotrienes contribute to aneurysm formation

Patient questions: Is mast cell disease autoimmune?

Autoimmune disease is when your body has an abnormal immune response to something that is a normal part of the body. There are more than eighty currently identified autoimmune diseases and they affect a significant population worldwide. At least 2% of women are estimated to have at least one autoimmune condition. Multiple sclerosis, rheumatoid arthritis and lupus are examples of autoimmune disease. Autoimmune diseases can affect small areas or multiple organs or targets throughout the body.

There are a number of possible causes of autoimmune disease. Some well supported theories include:
1. Molecular mimicry. This occurs when the body is exposed to an external danger and direct antibodies and immune defense against this danger. However, once the danger has been resolved, the antibodies and immune defense are directed toward damaging some normal part of the body that by happenstance looks like the dangerous thing. A classic example of this is development of rheumatic fever, PANDAS and other complications after a Streptococcus infection. The body makes antibodies to fight Strep, the Strep is killed and infection resolved, but the antibodies then attack things in the body that look like strep to the antibodies.
2. Genetic predisposition. Mutations and improper expression of genes that mediate tolerance, like HLA genes, can result in autoimmune disease. In these patients, these anomalies cause the body to fail to recognize itself as “safe”.
3. Cryptic determinants. This refers to the situation in which a hidden part of a normal structure in the body is not usually “seen” by the rest of the body. When that hidden part is exposed to the rest of the body, the immune system does not recognize it and attacks it, thinking it is dangerous. I imagine this as a waterway in a year of drought. A river has many small black rocks on the bottom. When the water is high, like most years, you cannot see these rocks. In a year of drought, the water level drops and you can the black rocks on the bottom. They were always a natural part of the riverbed, and they were always there, you just couldn’t see them. This can happen inside the body too. Sometimes your immune system sees things that were always there but not seen by it before.

The key feature unifying autoimmune diseases is that the immune system directly targets a part of the body that is normal and healthy. In lupus, the body makes antibodies that target the DNA inside our cells, which is not just normal but critically important to survival. It doesn’t target defective DNA, it targets regular old, keeps us alive, DNA.

Mast cell diseases are not autoimmune diseases. Mast cell diseases are not directly their attacks to a normal, healthy part of the body. In mast cell disease, mast cells are dysregulated and behave inappropriately. While this can damage parts of the body, this damage occurs due to the general inflammatory environment rather than because mast cells specifically targeted those parts of the body. Aberrant mast cells aren’t saying, “Quick, there’s an intruder in the liver! Let’s go get them!” when it’s just your regular liver hanging out. They are just so activated that mediator release could damage some cells in the liver, and in other places at the same time. The mast cell activation does not specifically target the liver in this scenario.

A confusing aspect of mast cell disease is that MCAS can occur secondary to autoimmune disease and many MCAS patients have autoimmune disease. In this patient population, the MCAS is probably induced by the inflammation caused by the autoimmune disease. Even still, while the primary autoimmune disease targets specific parts of the body, MCAS does not target specific parts of the body to attempt to destroy them.

The Sex Series – Part Six: Male pelvic dysfunction and mast cells

Chronic pelvic pain syndrome (CPPS) affects about 15% of male patients and 90% of patients with chronic prostatitis. Patients with these conditions experience pain in the pelvis, abdomen and genitalia, as well as urinary tract symptoms without evidence of infection. Pain can be intermittent or constant, and can interfere with daily activities including sitting, standing, urination and defecation.

CPPS also causes sexual symptoms. Painful ejaculation, erectile dysfunction, and other types of ejaculation dysfunction are all common in this patient group.  In one study, 40% of patients with CPPS were found to have erectile dysfunction.  In another, 72% of patients reported either erectile dysfunction or difficulty with ejaculation.

Pelvic floor dysfunction is a component of CPPS. Many of these patients have abnormally tense pelvic floor muscles, which can cause muscle spasm and obstruct bloodflow. CPPS patients are more likely than healthy controls to have vascular dysfunction associated with nitric oxide level. In a group of 146 patients with CPPS and verified pelvic floor spasm, 56% experienced painful ejaculation.  Visceral and myofascial pain and spasm of the muscles in the pelvic floor contribute to CPPS.  While pelvic floor dysfunction has been well researched for female patients, there are far fewer studies on pelvic floor dysfunction in men.  Biofeedback and pelvic floor physical therapy can resolve issues with erectile dysfunction and other sexual issues.

IL-17, expressed by special T cells called Th17 cells, is required to develop CPPS-like conditions in animal models. IL-17 triggers mast cell degranulation and secretion of many inflammatory molecules.  A number of mast cell mediators are elevated in patients with CPPS. IL-1b, TNF, IL-6 and IL-8 are higher in seminal fluid of these patients.  CCL2 and CCL3 expression is also increased. In the prostate of animals with a CPPS model, TNF, IL-17a, IFN-γ and IL-1b are all increased.

Tryptase has been found to induce pelvic pain. Levels of tryptase and carboxypeptidase A3 are higher in CPPS patients than in healthy controls.  Tryptase binds to a receptor called PAR2.  When tryptase binds to this PAR2 receptor, it is thought that it makes nerves oversensitive. If the PAR2 receptor is blocked, pelvic pain is mitigated.  In animal models where they cannot make tryptase-like products, pelvic pain does not develop in CPPS.

Nerve growth factor (NGF) is a mast cell mediator that has been implicated in CPPS. It is elevated in seminal plasma of CPPS patients and directly correlates with pain level. It is thought that NGF makes the peripheral nerves oversensitive and causes more nerve cells than usual to be present. NGF and tryptase were elevated in prostate secretions of most CPPS patients in a small patient group. Of note, NGF release occurs and increases weeks after initial symptoms.

In animal models, injecting cetirizine (H1 antihistamine) into the peritoneal cavity decreased pain by about 13.8%; ranitidine (H2 antihistamine), 6.1%; cromolyn, 31.4%. A combination of all three decreased pain by 69.3%. When cromolyn and cetirizine were used together, larger pain relief was achieved than when used individually, but this was not seen when using ranitidine and cromolyn together.  These data suggest that H2 signaling is not a major contributor in chronic pelvic pain in male patients.

Pelvic floor dysfunction is also common in heritable connective tissue diseases and is often present in hypermobile patients.


Done JD, et al. Role of mast cells in male chronic pelvic pain. Journal of Urology 2012: 187, 1473-1482.

Roman K, et al. Tryptase-PAR2 axis in experimental autoimmune prostatitis, a model for chronic pelvic pain syndrome. Pain 2014: 155 (7), 1328-1338.

Cohen D, et al. The role of pelvic floor muscles in male sexual dysfunction and pelvic pain. Sex Med Rev 2016; 4, 53-62.

Murphy SF, et al. IL17 mediates pelvic pain in experimental autoimmune prostatitis (EAP). PLoS ONE 2015, 10(5) : e0125623.


Glossary of mast cell related terms: P-Z

Parasympathetic nervous system: Part of the autonomic nervous system.  Regulates digestion and other functions.

Prostaglandin D2 (PGD2): The dominant prostaglandin produced by mast cells.

9a,11b-PGF2: a breakdown product of prostaglandin D2; can be measured to assess level of mast cell activation

Platelet activating factor (PAF): a mast cell mediator that correlates with severity of anaphylaxis; induces degranulation and release of leukotrienes and prostaglandins

Postural orthostatic tachycardia (POTS): increase of 30 bpm or more when standing in the absence of orthostatic hypotension.

Premedication: taking medication in advance of an event in order to suppress an undesirable reaction during the event, such as premedicating before surgery

Pre-stored: as relates to mast cell biology, mediators that are made inside the cell and stored in granules to be released at a later time

Progenitor cell: a cell that develops into another type of cell

Proliferation: growth and expansion of a cell population

Prostaglandin: a type of eicosanoid with wide ranging biological effects; PGD2 is the prostaglandin most abundantly produced by mast cells

Protracted anaphylaxis: a long episode of anaphylaxis symptoms despite treatment

Rare disease: a disease that affects only a small amount of people in a population; in the US, defined as affecting 200,000 people or less in the US

Rebound: a resurgence of symptoms after quelling symptoms earlier

Receptor: a protein on the outside of cells that bind specific molecules, causing a specific action to occur

Secretion: the release of molecules from inside the cell to the outside environment without degranulation

Sensitization: production of IgE specific to an allergen without obvious allergic reaction to the allergen

Serotonin: a neurotransmitter released by a number of cell types, including mast cells

Smouldering systemic mastocytosis (SSM): a form of SM in which organ damage and failure could eventually occur; diagnosed when someone with SM has two or more B findings

Splenomegaly: swelling of the spleen

Stem cell factor (SCF): a mast cell growth factor; SCF binds to CKIT and tells mast cells to stay alive and make more mast cells

Sympathetic nervous system: Part of the autonomic nervous system.  Controls the fight or flight response

Systemic mastocytosis (SM): a proliferative mast cell disease in which too many mast cells are produced

Systemic mastocytosis with associated clonal hematologic non-mast cell lineage disease (SM-AHNMD): co-occurrence of SM with another proliferative blood cell disorder, such as essential thrombocythemia or chronic myelogenous leukemia

Tachycardia: rapid heartbeat

Third spacing: when fluid is forced out of a place the body can use it and becomes trapped, such as ascites or angioedema

TLR: toll like receptor; receptors on the outside of many cells (including mast cells) that activate immune response to infections

Telangiectasia macularis eruptive perstans (TMEP): a less common form of cutaneous mastocytosis.  Found almost exclusively in adults.

Tryptase: a mast cell mediator; when tested outside of a symptomatic episode, it is used to measure the baseline amount of mast cells present ; when tested during a symptomatic episode, it can be used to identify mast cell activation

Urticaria pigmentosa (UP): also called maculopapular cutaneous mastocytosis (MPCM).  The most common form of cutaneous mastocytosis.

Urticaria: hives

Wheal and flare response: a reaction marked by redness and raised, taut skin due to histamine release

Glossary of mast cell related terms: M-O

Mast cell: white blood cells with important roles in allergy, anaphylaxis and immune defense that live in tissues and only briefly circulate in the blood; also called mastocytes

Mast cell activation: a change in mast cell behavior that occurs following exposure to a trigger that may indicate allergy or infection; a state in which mast cells release mediators, both through degranulation and through secretion; in some instances, culminating in anaphylaxis

Mast cell disease: a disease that occurs due to fundamental error in mast cell proliferation or activation physiology

Mast cell disorder: used synonymously with mast cell disease

Mast cell leukemia: a very aggressive mast cell disease marked by massively excessive proliferation of mast cells, culminating in progressive organ failure

Mast cell sarcoma: a very aggressive mast cell disease that presents as a connective tissue tumor and progresses to mast cell leukemia

Mast cell stabilizer: a medication that decreases the likelihood of mast cell degranulation and mediator release

Mastocytic enterocolitis: the phenomenon of having too many mast cells in the GI tract; originally described as more than 20 mast cells/ high power field, but there is no consensus on how many mast cells in a field is too many

Mastocytoma: a benign mast cell tumor. Most frequently occurs on skin, but can occur elsewhere in the body.

Mast cell activation disease (MCAD): usually a catchall term for mast cell diseases, although some people exclude cutaneous mastocytosis from this category

Mast cell activation disorder (MCAD): an alternate term for mast cell activation syndrome (MCAS); a non-proliferative mast cell disease that is usually diagnosed by detecting an elevation in mast cell mediators

Mast cell activation syndrome (MCAS): a non-proliferative mast cell disease that is usually diagnosed by detecting an elevation in mast cell mediators; occurs secondary to a known condition or idiopathically, in which no primary condition is identified; “primary” mast cell activation syndrome has its own name, MMAS

Mediator: a molecule released from a cell that has effects on the environment outside the cell; mast cells release dozens of mediators

Monoclonal mast cell activation syndrome (MMAS) : a mast cell disease diagnosed when a patient meets some criteria for SM but not enough for an SM diagnosed

Monophasic anaphylaxis: an anaphylactic event in which symptoms resolve following administration of medication and do not recur at a later time

Mutation: a change in the genetic sequence that can affect the way a gene is expressed, or in the way its gene product is made or functions

Myeloid: concerning cells that develop into granulocytes, monocytes, platelets or erythrocytes

Myeloproliferative neoplasm: a disorder caused by aberrant proliferation of a myeloid cell line, such as SM, myelofibrosis, essential thrombocythemia or polycythemia vera, among others

Neoplasm: an abnormal cell

N-methylhistamine: a breakdown product of histamine; can be tested for to assess mast cell activation

Oral allergy syndrome: An IgE reaction to raw fruits and vegetables that causes itching and swelling in the mouth and throat.

Orthostatic hypotension (OH): reduction of systolic blood pressure of more than 20 mm Hg or diastolic blood pressure of more than 10 mm Hg within three minutes of standing.

Orthostatic intolerance (OI): symptoms that occur when transitioning to a standing position