The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 10

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

17. Does mast cell disease impact mood, anxiety, and depression?
Yes. This has been described in literature for over 30 years. In 1986, a paper described a series of patients with systemic mastocytosis who had severe psychiatric symptoms as a result of their disease. It was called “mixed organic brain syndrome”.
Depression, anger, bipolar disorder, attention deficit disorders, anxiety, irritating, and panic disorders have all been associated with mast cell disease.
• One study found that in a group of patients with cutaneous mastocytosis and systemic mastocytosis, 75% of the patients had symptoms of depression. In another study, 60% had symptoms of depression or anxiety.
• Many patients have been diagnosed with a psychiatric condition before learning that they have mast cell disease. For many mast cell patients, managing their diseases lessens the severity of their psychiatric symptoms. Antihistamines have been reported many times to improve these symptoms.
• Mast cells are often sitting right next to nerve cells throughout the body. Mast cells are found in large numbers in the brain. Chemicals released by mast cells can cause psychiatric symptoms.
• Some of the chemicals released by mast cells are specifically intended to talk to nerve cells. Histamine is one such chemical. When histamine is not released in the right amounts at the right times, it can affect how other chemicals are released. Some of these chemicals are also for cells to talk to nerves, like serotonin and dopamine. Mast cells can also release serotonin.

18. Are medications for depression, anxiety or other psychiatric conditions used in mast cell patients?
Yes. As with every medication, only you and your care team can decide if a medication is safe for you. No medication is universally safe or always dangerous.
Benzodiazepines are usually well tolerated in mast cell patients. Benzodiazepines actually interact with mast cells and can make them release fewer chemicals. (Be aware that the IV forms of these medications sometimes have alcohol in them).
SSRIs are sometimes taken by mast cell patients. Mast cell patients should be cautious because they can increase serotonin levels and mast cells can also release serotonin.
• Tricyclic antidepressants are more commonly used in mast cell patients. Tricyclic antidepressants actually work as antihistamines, too.
• Other drugs that can manage psychiatric symptoms, like mirtazapine, olanzapine, and quetiapine, also have antihistamine properties.
For more detailed reading, please visit these posts:


Neuropsychiatric features of mast cell disease: Part 1 of 2

Neuropsychiatric features of mast cell disease: Part 2 of 2

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)

Mood disorders and inflammation: High cortisol and low serotonin (Part 2 of 4)

There are multiple suspect pathways for causation of mood dysregulation in the setting of inflammation. One well described model hinges upon the ability of inflammatory mediators to impact the HPA axis, a system of hormone release that drives many physiologic functions in addition to the stress response.  Briefly, the central pathway of the HPA axis is that CRH causes production of ACTH, which causes production of cortisol, a stress hormone and a very potent anti-inflammatory under most circumstances.  Many molecules can affect the signaling of the HPA axis and contribute to inappropriate hormone regulation.

IL-1, IL-6, TNF and IFN-a are all inflammatory mediators released by mast cells and other cells. These mediators all activate the HPA axis, resulting in high production of CRH, ACTH and cortisol via a series of intertwined mechanisms. At the same time, inflammation also makes cortisol less effective.  There are several ways for this to occur. Inflammation can cause cells to make fewer receptors for cortisol, meaning that no matter how much cortisol is made, only a small fraction will be able to act on cells.  Persistently high cortisol levels decrease production of other anti-inflammatory molecules and molecules that mediate the anti-inflammatory action of cortisol.  High cortisol also tells the HPA axis that it doesn’t need to make more cortisol, so even though more may actually be necessary, your body doesn’t know that.

All of these factors coalesce to form a reality where cortisol may be elevated but with little anti-inflammatory effect because of the changes I mentioned above. High cortisol is associated with mood symptoms.

Decrease of serotonin activity is also seen in mood disorders. Tryptophan is a precursor to serotonin, a hormone and neurotransmitter that heavily regulates mood.  Cortisol increases the activity of a molecule called tryptophan 2,3-dioxygenase (TDO), which removes the amino acid tryptophan from the pool of molecules to break down. Inflammatory molecules like interferon increase activity of the enzyme IDO, which decreases serotonin production.  IDO breaks down tryptophan to molecules that cannot be made into serotonin, such as kynerenin and quinolonic acid.  These metabolites have been observed as elevated in models of depression and anxiety.

Another way that inflammatory mediators affect the action of serotonin is to hasten its degradation. Both TNF and IL-6 increase the breakdown of serotonin to 5-HIAA.


Furtado M, Katzman MA. Examining the role of neuroinflammation in major depression. Psychiatry Research 2015: 229, 27-36.

Rosenblat JD, et al. Inflamed moods: a review of the interactions between inflammation and mood disorders. Progress in Neuro-Psychopharmacology & Biological Psychiatry 2014; 53, 23-34.

Mood disorders and inflammation: Mediators (Part 1 of 4)

Mood disorders are the leading cause of disability in many countries around the world. Depression alone affects a staggering number of people, currently thought to be about 350 million people worldwide.  Its prevalence and diagnosis is increasing to such an extent that the WHO expects it to be the primary cause of global disease burden in less than 15 years.

Mood disorders are commonly found in patients diagnosed with inflammatory conditions.  Cardiovascular disease, diabetes, metabolic syndrome, asthma, allergies and many autoimmune diseases co-occur with these psychiatric conditions.  While providers are often tempted to attribute depression, anxiety and maladaptive behaviors to the stress of having chronic health issues, a significant body of evidence firmly supports the idea that mood disorders are themselves inflammatory conditions and therefore biologically ordained. Furthermore, having a mood disorder can affect prognosis in some diseases.

A number of inflammatory molecules participate in immune response, including histamine, prostaglandins, bradykinin, leukotrienes, CRP, interferon, cortisol and cytokines.  These substances are released in response to physical stresses such as infection, trauma or disease process.  Psychological stress also triggers inflammatory response with increases of molecules such as IL-6, IL-1b, TNF and CRP.

Several studies have definitively found that mood symptoms are associated with increased levels of inflammatory markers.  PGE2, CRP, TNF, IL-1b, IL-2 and IL-6 were all elevated in both peripheral blood and cerebrospinal fluid in patients with major depressive disorder.  A massive 25-80% of hepatitis C patients experience depressive symptoms when they begin treatment with interferon, a potent inflammatory molecule. Elevated interferon and IL-2 levels have been observed early in the depressive event.

In human patients, studies have simulated an inflammatory response by inoculation with toxins, proteins associated with infectious organisms, or interferon. In one study, an inflammatory response was provoked by inoculation with Salmonella endotoxin.  While they suffered no physical symptoms, anxiety, depressed mood and decreased memory function was observed along with elevated TNF, IL-6 and cortisol levels.  Another study found that inoculation with LPS (a substance found in bacterial cell membranes) triggered a dose dependent increase in IL-6, IL-10, TNF, cortisol and norepinephrine, which in turn triggered a dose dependent increase in anxiety, “poor mind” and decreased long term memory functions.


Furtado M, Katzman MA. Examining the role of neuroinflammation in major depression. Psychiatry Research 2015: 229, 27-36.

Rosenblat JD, et al. Inflamed moods: a review of the interactions between inflammation and mood disorders. Progress in Neuro-Psychopharmacology & Biological Psychiatry 2014; 53, 23-34.


Symptoms, mediators and mechanisms: A general review (Part 2 of 2)


Gynecologic symptoms    
Symptom Mediators Mechanism
Irregular and painful menstruation Histamine (H1), bradykinin Smooth muscle constriction
Uterine contractions Histamine (H1), serotonin, bradykinin Smooth muscle constriction

Increased estrogen



Neurologic symptoms    
Symptom Mediators Mechanism
Appetite dysregulation Histamine (H1), histamine (H3), leptin Dysfunctional release of neurotransmitters, suppression of ghrelin
Disorder of movements Histamine (H2), histamine (H3) Dysfunctional release of neurotransmitters, increases excitability of cholinergic neurons
Memory loss Histamine (H1), histamine (H3) Dysfunctional release of neurotransmitters
Headache Histamine (H1), histamine (H3), serotonin (low) Dysfunctional release of neurotransmitters


Low serotonin


Decreased blood flow to brain

Depression Serotonin (low), TNF, histamine (H1) Low serotonin

Disordered release of dopamine

Irregular sleep/wake cycle Histamine (H1), histamine (H3), PGD2 Dysfunctional release of neurotransmitters
Brain fog Histamine (H3), inflammatory cytokines Dysfunctional release of neurotransmitters, neuroinflammation
Temperature dysregulation Histamine (H3) Dysfunctional release of neurotransmitters, dysfunctional release of catecholamines



Miscellaneous symptoms    
Symptom Mediators Mechanism
Bleeding diathesis (tendency to bleed easily) Tryptase, heparin Participation in anticoagulation pathways

Neuropsychiatric features of mast cell disease: Part 2 of 2

Mast cell activation can induce neuropsychiatric symptoms. Degranulation has been linked previously to headache. It is possible that peptidergic and cholinergic neurons receive mast cell mediators and that this plays a role in headache pathology.  TNF is speculated to participate in depression.  Histamine may cause memory deficits, although there is conflicting information on this topic. Some patients have improvement in neuropsychiatric symptoms with antihistamines.

Mastocytosis patients who have GI and neuropsychiatric symptoms often have low serum serotonin.  Tryptophan is a precursor to serotonin. Plasma tryptophan is also often low in mastocytosis patients, while plasma IDO1 (indoleamine-2,3-dioxygenase 1) activity is higher. IDO1 breaks down tryptophan through an alternate pathway that does not form serotonin. In this pathway, IDO1 breaks down tryptophan, forming kynurenic acid and quinolinic acid.  The accumulation of these substances could explain the fatigue and cognitive impairment in mastocytosis patients.  Low tryptophan and low serotonin in this population were associated with perceived stress and depression.

Treatment of neuropsychiatric symptoms in mast cell patients can include a variety of medications.   SSRI medications can reduce fatigue and depression in some inflammation models.  Some mast cell patients take these medications, usually with low starting doses in case mast cell degranulation in these people has conversely led to higher serotonin levels.  Bupropion, SNRIs and tricyclic medications are also commonly used for depressive symptoms in many chronic illness populations.

Some tricyclic antidepressants have antihistamine properties, with doxepin being a common choice.  Another tricyclic, amitriptyline, can inhibit release of mast cell mediators. Mianserin and mirtazapine can be prescribed for insomnia but also have antihistamine properties. Aprepitant could potentially be used in treatment of depression and cognitive impairment in mastocytosis and MCAS patients. Prochloperazine also decreases mast cell mediator release. Amantadine has improved depression and fatigue symptoms in multiple sclerosis patients. Inhibition of TNF with infliximab has improved depression in patients with high levels of inflammation.

Kynurenic acid, formed in the alternate tryptophan breakdown pathway described above, can block acetylcholine receptors, causing neurologic symptoms.  A7 agonists like nicotine could potentially overcome this effect.  Quinolinic acid binds at the NMDA receptor, cause neurologic symptoms.  Ketamine, an NMDA antagonist, can produce significant improvements in depressive symptoms in treatment resistant depression. As quinolinic acid is typically present in higher levels than kynurenic acid in mastocytosis patients, ketamine might offer a treatment for these patients with depression and high perceived stress.

Masitinib, a tyrosine kinase inhibitor, was shown to decrease depression, anxiety and cognitive difficulties in a significant amount of mastocytosis patients. Mindful meditation may also help patients to lessen activation caused by psychological stress and therefore decreasing biological stress.


Georgin-Lavialle S, et al. Mastocytosis in adulthood and neuropsychiatric disorders. Translational Resarch 2016; x:1-9.

Georgin-Lavialle S, et al. Leukocyte telomere length in mastocytosis: correlations with depression and perceived stress. Brain Behav Immun 2014; 35: 51-57.

Moura DS, et al. Neuropsychological features of adult mastocytosis. Immunol Allergy Clin North Am 2014; 34(2): 407-422.

Moura DS, et al. Depression in patients with mastocytosis: prevalence, features and effects of masitinib therapy. PLoS One 2011, 6: e.26375.

Moura DS, et al. Evidence for cognitive impairment in mastocytosis: prevalence, features and correlations to depression. PLoS One 2012, 7: e.39468.

Smith JH, et al. Neurologic symptoms and diagnosis in adults with mast cell disease. Clin Neurol Neurosurg 2011, 113: 570-574.

Neuropsychiatric features of mast cell disease: Part 1 of 2

The fact that psychiatric symptoms occur as a function of mast cell disease on the nervous system is common knowledge to patients but less acknowledged by providers.  A significant population of mast cells is found in the brain in close association with both blood vessels and nerve cells.  Mast cells are present in large numbers in the hypothalamus, which regulates stress response, emotion and cognition; the amygdales, near the pituitary gland; and the thalamus.  Lesions and structural changes in the thalamus have previously been associated with altered perception of pain and emotional reactivity.

One study found that in a group of 88 patients with indolent systemic mastocytosis (ISM) and cutaneous mastocytosis (CM), 75% reported depressive symptoms.  In another study, a group of 288 mastocytosis patients had a prevalence of 60% depressive and anxiety-type symptoms.  The depressive symptoms seen most often in mastocytosis patients are affective and cognitive symptoms (depressed mood, low motivation, feelings of guilt and failure; and anxio-somatic symptoms (physical and mental effects of anxiety, insomnia).  Psychomotor difficulties (slowing of thought processes and/or neurologic control of movement) and lack of insight were rare in these patients.

Depression is often assessed using the Hamilton Depression Rating Scale.  This tool may not be ideal for use in mast cell patients because the somatic symptoms correlated with depression are often the same as physical symptoms of mast cell disease.  When excluding symptoms that could be from mastocytosis rather than depression, patients still had a high prevalence of sadness and loss of motivation.

One mastocytosis cohort reported 38.6% had cognitive impairment of some kind. Inability to focus and pay attention is the cognitive symptom most commonly reported by mastocytosis patients.  This was not linked to depression, age, education or staging of mastocytosis.  Importantly, it was also independent of amount of antihistamine use.  Memory impairment was also not related to age or education.  Cognitive difficulties were found to be much more prevalent in mastocytosis patients than in other chronic disease populations.

Fatigue is a common neuropsychiatric symptom for mast cell patients and has been seen in populations with both mastocytosis and mast cell activation syndrome.  Patients who have moderate to severe fatigue often experience pain and cognitive deficits.  The level of fatigue can be disabling as it makes it difficult to focus or perform even simple tasks.

35% of mastocytosis patients in one study reported 35% had either acute or chronic headaches.  37.5% had migraines, while 17.2% had tension type headaches.  Headache patients often reported episodic flushing or itching at the time of the headache. In the migraine group, 66% experienced aura symptoms.  Overall, 39% of patients in this group with or without migraines experienced aura symptoms, usually visual.

Exaggeration of the stress response could explain neuropsychiatric symptoms in mast cell patients. In one population, 42% of patients perceived their stress level to be high. Persistent stress response could lead to negative emotions.  These symptoms could be reinforced by mast cell hyperactivity in the brain, which can affect stress response, emotionality and cognition.


Georgin-Lavialle S, et al. Mastocytosis in adulthood and neuropsychiatric disorders. Translational Resarch 2016; x:1-9.

Georgin-Lavialle S, et al. Leukocyte telomere length in mastocytosis: correlations with depression and perceived stress. Brain Behav Immun 2014; 35: 51-57.

Moura DS, et al. Neuropsychological features of adult mastocytosis. Immunol Allergy Clin North Am 2014; 34(2): 407-422.

Moura DS, et al. Depression in patients with mastocytosis: prevalence, features and effects of masitinib therapy. PLoS One 2011, 6: e.26375.

Moura DS, et al. Evidence for cognitive impairment in mastocytosis: prevalence, features and correlations to depression. PLoS One 2012, 7: e.39468.

Smith JH, et al. Neurologic symptoms and diagnosis in adults with mast cell disease. Clin Neurol Neurosurg 2011, 113: 570-574.

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.


Hypermobility Type Ehlers Danlos Syndrome and Autonomic Dysfunction (Part One)

Ehlers Danlos Syndrome (EDS) is a heritable connective tissue disease with six major subtypes. EDS occurs in approximately 1/5000 births.  Classical EDS (cEDS) and hypermobility type EDS (HEDS or ht-EDS) are the most common forms, with approximately 90% of patients having one of these types.  Vascular EDS (vEDS) affects about 5% of EDS patients.  The remaining types are rare. Generally, EDS patients demonstrate hypermobility of joints, excessive stretchiness of the skin (hyperextensibility) and fragility of soft tissues.

Ehlers Danlos is diagnosed by clinical evaluation and diagnostic testing.  Mutations affecting structure of collagen, a key component of connective tissue, have been identified for cEDS and vEDS.  For hypermobility type EDS, no consistent genetic anomality has been found.  As a result, diagnosis of this subtype relies upon patient history and clinical examination.

The Beighton scale is a nine point scale for evaluating hypermobility.  One point is granted for each: elbow hyperextended more than 10°, knee hyperextended more than 10°, thumb that can be touched to the forearm, and fifth finger that can be passively bent back more than 90°.  One further point is granted for being able to place the palms flat on the floor with knees fully extended.  A score of 5 points or more is suggestive of joint hypermobility, a major criterion for diagnosis of HEDS.

In addition to an appropriate Beighton score, soft skin with normal or slight hyperextensibility and absence of significant soft tissue abnormalities are also important for HEDS diagnosis.  Excessive skin hyperextensibility and serious fragility of connective tissue could be indicative of other forms of EDS.

Hypermobility type EDS was regarded for many years as a benign laxity of the joints.  In recent years, this position has been debunked, though this belief still persists for many medical providers. Hypermobility and musculoskeletal pain were previously recognized as the dominant manifestations, but we now know that HEDS can cause cardiovascular, gastrointestinal, genitourinary and neurologic symptoms, among others.  In fact, the aspects of this disease that aren’t musculoskeletal are the most disabling and are correlated with lower quality of life

Symptoms arising from dysfunction of the autonomic nervous system have serious impact on quality of life as demonstrated in a number of conditions, including chronic fatigue syndrome and fibromyalgia.  Autonomic dysfunction can be assessed with an Autonomic Symptom Profile (ASP), a questionnaire of 169 questions that evaluates symptoms in eight broad categories: orthostatic (upright posture), secretomotor (secretion of substances by glands), urinary, GI, pupillomotor (movement of the pupil), vasomotor (changing diameter of blood vessels), reflex syncope (dysfunction of blood pressure and heart rate) and sleep function. These functions are all controlled by the autonomic nervous system.


de Wandele I, et al. Dysautonomia and its underlying mechanisms in the hypermobility type of Ehlers-Danlos syndrome. Seminars in Arthritis and Rheumatism 2014, 44: 93-100.

de Wandele I, et al. Autonomic symptom burden in the hypermobility type of Ehlers-Danlos syndrome: A comparative study with two other EDS types, fibromyalgia, and healthy controls. Seminars in Arthritis and Rheumatism 2014, 44: 353-361.

Wallman D, et al. Ehlers-Danlos Syndrome and Postural Tachycardia Syndrome: A relationship study. Journal of Neurological Sciences 2014, 340: 99-102.

Mast cells in nerve pain

Mast cells are heavily involved in the generation and sensation of pain. The role of mast cells in neurogenic pain (also called nerve pain or neuropathy) is well established and is responsible for a number of painful conditions.

Pain is transmitted like this:

  1. You first feel the pain in nerve endings called nociceptors.
  2. These nerve endings and capillaries in the nearby tissue form a “pain unit” that sends pain signals.
  3. Mast cells are often found close to these nerve endings and capillaries. They release mediators like prostaglandins, histamine and bradykinin.
  4. Nociceptors release mediators like substance P, VIP and CRH, which activate mast cells.
  5. Mast cells then release mediators that increase permeability of the vessels and sensitize the nociceptors. This cycle, in which the nerve endings activate mast cells and the mast cells activate the nerve endings, is called a positive feed back loop. The end result is neurogenic inflammation, or inflammation caused by nerves.

Mast cells can communicate with nerve endings in a number of ways. The first way is by releasing mediators, which may bind to receptors on the nerve cells. A second way is by mast cells sticking to nerve cells through molecules like CADM-1 and N-cadherin; they are able to send signals when their membranes are touching. A third way is by the nerve cells ingesting mediators released by mast cells. These mediators are then transported to other nerve cells, where it can affect which genes are turned on and used.

Mast cells also draw other immune cells to the site of inflammation, like neutrophils and T cells. These cells also release mediators that increase pain, forming another positive feedback loop. The result is that inflammation can spread beyond the initial site of pain, causing a secondary, larger pain response. Hyperalgesia is an exaggerated pain response that is more severe than expected based upon the injury. Mast cells are thought to be directly involved in hyperalgesia and histamine is thought to cause this heightened pain sensation.

Chronic pain has been associated with mast cell degranulation. Degranulation close to colonic nerves is correlated with abdominal pain in IBS patients. Tryptase and histamine can also activate enteric nerves, causing the nerves to be oversensitive. Esophageal pain is also a function of mast cell degranulation.

The specific mechanism of bladder pain due to interstitial cystitis is not clear. However, mast cells are often elevated in IC patients, and contribute to inflammation. It is thought that activation of bladder nerves causes release of substance P by local nerve endings, which activates mast cells.

Overly sensitive and painful skin is sometimes a function of mast cells as well. A significant increase in mast cells has been found in the dermis of fibromyalgia patients. Chronic granulomatous inflammation of the skin causing pain has also been found to be from degranulation of mast cells.



Heron, Anne, Dubayle, David. 2013. A focus on mast cells and pain. Journal of Neuroimmunology 264 (2013) 1–7.

Parada, C.A., Tambeli, C.H., Cunha, F.Q., Ferreira, S.H., 2001. The major role of peripheral release of histamine and 5-hydroxytryptamine in formalin-induced nociception. Neuroscience 102, 937–944.

Theoharides, T.C., Kempuraj, D., Sant, G.R., 2001. Mast cell involvement in interstitial cystitis: a review of human and experimental evidence. Urology 57, 47–55.

Theoharides, T.C., Donelan, J., Kandere-Grzybowska, K., Konstantinidou, A., 2005. The role of mast cells in migraine pathophysiology. Brain Res. Brain Res. Rev. 49, 65–76.

Gao, G., Ouyang, A., Kaufman, M.P., Yu, S., 2011. ERK1/2 signaling pathway in mast cell activation-induced sensitization of esophageal nodose C-fiber neurons. Dis. Esophagus 24, 194–203.