Symptoms, mediators and mechanisms: A general review (Part 1 of 2)

Skin symptoms    
Symptom Mediators Mechanism
Flushing Histamine (H1), PGD2 Increased vasodilation and permeability of blood vessels

Blood is closer to the skin and redness is seen

Itching Histamine (H1), leukotrienes LTC4, LTD4, LTE4, PAF Possibly stimulation of itch receptors or interaction with local neurotransmitters
Urticaria Histamine (H1), PAF, heparin, bradykinin Increased vasodilation and permeability of blood vessels and lymphatic vessels

Fluid is trapped inappropriately between layers of skin

Angioedema Histamine (H1), heparin, bradykinin, PAF Increased vasodilation and permeability of blood vessels and lymphatic vessels

Fluid is trapped inappropriately between layers of tissue

 

Respiratory symptoms    
Symptom Mediators Mechanism
Nasal congestion Histamine (H1), histamine (H2), leukotrienes LTC4, LTD4, LTE4 Increased mucus production

Smooth muscle constriction

Sneezing Histamine (H1), histamine (H2), leukotrienes LTC4, LTD4, LTE4 Increased mucus production

Smooth muscle constriction

Airway constriction/ difficulty breathing Histamine (H1), leukotrienes LTC4, LTD4, LTE4, PAF Increased mucus production

Smooth muscle constriction

 

Cardiovascular symptoms    
Symptom Mediators Mechanism
Low blood pressure Histamine (H1), PAF,  PGD2, bradykinin Decreased force of heart contraction

Increased vasodilation and permeability of blood vessels

Impact on norepinephrine signaling

Change in heart rate

Presyncope/syncope (fainting) Histamine (H1), histamine (H3), PAF, bradykinin Increased vasodilation and permeability of blood vessels

Decrease in blood pressure

Dysfunctional release of neurotransmitters

High blood pressure Chymase,  9a,11b-PGF2, renin, thromboxane A, carboxypeptidase A Impact on renin-angiotensin pathway

Impact on norepinephrine signaling

Tightening and decreased permeability of blood vessels

Tachycardia Histamine (H2), PGD2 Increasing heart rate

Increasing force of heart contraction

Impact on norepinephrine signaling

Arrhythmias Chymase, PAF, renin Impact on renin-angiotensin pathway

Impact on norepinephrine signaling

 

Gastrointestinal symptoms    
Symptom Mediators Mechanism
Diarrhea Histamine (H1), histamine (H2), bradykinin, serotonin Smooth muscle constriction

Increased gastric acid secretion

Dysfunctional release of neurotransmitters

Gas Histamine (H1), histamine (H2), bradykinin Smooth muscle constriction

Increased gastric acid secretion

Abdominal pain Histamine (H1), histamine (H2), bradykinin, serotonin Smooth muscle constriction

Increased gastric acid secretion

Dysfunctional release of neurotransmitters

Nausea/vomiting Histamine (H3), serotonin Dysfunctional release of neurotransmitters
Constipation Histamine (H2), histamine (H3), serotonin (low) Dysfunctional release of neurotransmitters

 

The Sex Series – Part Nine: Female pelvic floor dysfunction (2 of 2)

Muscular dysfunction in the pelvic floor starts when something happens that causes an injury or large scale inflammation to the pelvic floor.  This causes a large scale release of calcium, which causes the muscle to become too tight (hypertrophic).  As a result of this tightness, metabolism in the tissues increases and substances like histamine, serotonin and prostaglandins are released.  These mediators trigger neurologic pain perception.   The pain causes tightness, which causes more pain, and the cycle continues.

Hypertrophic muscles become musculodystrophic as fibrosis occurs.  The muscle becomes atrophied and is replaced by less extensible connective tissue.  As a result, the muscles aren’t as flexible as they should be. This also means that they cannot relax normally.  This activates trigger points in the pelvic floor and increases tone and spasm in pelvic structures, including the bladder, uterus, and rectum.

Treatment for pelvic floor dysfunction of women is very well described in literature.  It relies largely upon patient education and compliance with various exercises to retrain the muscles to relax completely at will.  Trigger-point pressure, both internal and external, can be applied by the patient or partner to help the muscles relax.  Vaginal or anal dilators, vaginal cones and bladder training can also be effective. Physical therapy including myofascial release and biofeedback are also important to treatment.

While initial treatment of PFD can be complex and time-consuming, the results are very good.  One study followed a cohort for ten years. 71% of women in this cohort reported major reduction or elimination of pain level following physical therapy and exercises done at home. After ten years, 89% of women reported major reduction or elimination of pain.  Many patients continued their home exercises during that time.

 

References:

Bortolami A, et al. Relationship between female pelvic floor dysfunction and sexual function: an observational study. J Sex Med 2015; 12: 1233-1241.

Hartmann D, Sarton J. Chronic pelvic floor dysfunction. Best Practice & Research Clinical Obstetrics and Gynaecology 2014, 28: 977-990.

Espuña-Pons M, et al. Pelvic floor symptoms and severity of pelvic organ prolapse in women seeking care for pelvic floor problems. European Journal of Obstetrics and Gynecology and Reproductive Biology 2014, 177: 141-145.

Ramalindam K, Monga A. Obesity and pelvic floor dysfunction. Best Practice and Research Clinical Obstetrics and Gynaecology 2015, 29: 541-547.

Graziottin A, et al. Mast cells in chronic inflammation, pelvic pain and depression in women. Gynecol Endocrinol 2014; 30 (7): 472-477.

Ahangari A. Prevalence of chronic pelvic pain among women: an updated review. Pain Physician 2014; 17: e141-147.

The Sex Series – Part Eight: Female pelvic floor dysfunction (1 of 2)

Chronic pelvic pain (CPP) in women is staggeringly common, with incidence ranging from 5.7-26.6%, depending on the study. CPP is marked by intermittent or constant pain in the lower abdomen or pelvis, lasts at least six months, and is not associated directly with menstruation, pregnancy or intercourse. Mast cells are known to be involved in the inflammatory processes of these conditions and are therefore linked to CPP.

It can be caused a wide variety of conditions that affect organs or structures in the pelvis, including endometriosis, inflammatory bowel diseases affecting the lower tract, interstitial cystitis, ovarian cysts and hypermobility type Ehlers Danlos Syndrome (HEDS).  Over half of women with CPP report chronic bladder pain, for which interstitial cystitis is a common cause.  Interstitial cystitis is widely accepted to be a mast cell mediated disease.

Despite the frequency of CPP, many exploratory surgeries to identify the cause find nothing (28-55%). Chronic pain from these conditions alters the way the sensory nerves in the pelvic cavity send signals to the spinal cord.  This in turn disrupts interpretation of pain and sensation by the nerves, creating more visceral pelvic pain.

Pelvic floor dysfunction (PFD) affects about 26% of women with CPP.  This dysfunction can cause embarrassing and disabling symptoms, including urinary and fecal incontinence. Pelvic organ prolapse occurs when organs such as the bladder move out of the correct position and impinge on other structures, such as the vagina. Pelvic organ prolapse can be called by pelvic floor dysfunction and it can cause pelvic floor dysfunction.

Sexual dysfunction affects 15-65% of PFD patients. PDF interferes with correct function of a number of muscles, including the levator ani, which hold urogenital structures in place and allow them stretch and contract during penetration and orgasm.  Patients with pelvic organ prolapse often feel a bulge pushing against the vaginal wall that interferes with vaginal penetration.  Vulvodynia, vestibulodynia, vaginismus and painful intercourse are commonly seen in PFD.

In PDF patients, muscles in the pelvic floor can be hypotonic (not tight enough), hypertonic (too tight), or have normal tone. Hypotonic dysfunction is more likely to cause incontinence, bladder symptoms and pelvic organ prolapse.  Hypertonic dysfunction is associated much more with pain and sexual dysfunction. Reduction of the high tone is necessary to reduce pain.

References:

Bortolami A, et al. Relationship between female pelvic floor dysfunction and sexual function: an observational study. J Sex Med 2015; 12: 1233-1241.

Hartmann D, Sarton J. Chronic pelvic floor dysfunction. Best Practice & Research Clinical Obstetrics and Gynaecology 2014, 28: 977-990.

Espuña-Pons M, et al. Pelvic floor symptoms and severity of pelvic organ prolapse in women seeking care for pelvic floor problems. European Journal of Obstetrics and Gynecology and Reproductive Biology 2014, 177: 141-145.

Ramalindam K, Monga A. Obesity and pelvic floor dysfunction. Best Practice and Research Clinical Obstetrics and Gynaecology 2015, 29: 541-547.

Graziottin A, et al. Mast cells in chronic inflammation, pelvic pain and depression in women. Gynecol Endocrinol 2014; 30 (7): 472-477.

Ahangari A. Prevalence of chronic pelvic pain among women: an updated review. Pain Physician 2014; 17: e141-147.

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.

References:

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 Four)

The relationship between Ehlers Danlos Syndrome and dysautonomia, the dysfunction of autonomic nervous system, is currently being elucidated.  There is a correlation between hypermobility and autonomic symptoms. One study found that in patients with autonomic dysfunction, 18% had EDS, compared to the control group, in which only 4% had EDS.

Ehlers Danlos Syndrome alters collagen structure throughout the body. In HEDS, this usually affects the skin less than in other types of EDS.  In the cardiovascular system, this contributes to vascular laxity, which allows excessive dilation of the blood vessels, causing orthostatic intolerance. Importantly, you do not see the spontaneous rupture of blood vessels seen in VEDS.

In HEDS, connective tissue defects in the GI tract lead to dysfunctional peristalsis (contraction of GI tract to move food through it), excessive stretching or swelling, dysregulation of intestinal permeability and damage to the epithelial cells of the GI tract. Without proper connective tissue support, the bladder can become distended or impinge on other structures, as in cystocele.  HEDS frequently causes weakness in the pelvic floor and can lead to prolapse of pelvic organs.

Pain and fatigue are often attributed to dysautonomia in EDS patients, but it could also be caused by HEDS. Peripheral neuropathy is prevalent in HEDS and can drive pain in this population.  Many HEDS patients have sensory pain, such as tingling, pins and needles, numbness, radiating or burning pain. If the autonomic nervous system is responsible for the pain signals, it could provide a link between dysautonomia and pain. Chronic pain and inflammation can change the structure and behavior of the nervous system, making it easier to transmit pain signals.  Orthostatic intolerance can activate the sympathetic nervous system, part of the autonomic nervous system, contributing to these types of symptoms.

By contrast, many HEDS patients are known to frequently have anxiety, palpitations, dizziness, shortness of breath and high affective distress.  Rather than being from HEDS directly, these are likely from dysautonomia.

References:

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.

Phantom

I have always been fascinated by both the human body and the diseases that affect it. When I was about ten years old, my parents bought me a medical dictionary. I read it cover to cover. I wrote little stories about people with Legionnaire’s Disease and Tetrology of Fallot, describing the symptoms and treatments in vivid detail.

It was in this dictionary that I first read about phantom pain. It always made a weird sort of sense to me. Bodies are creatures of habit, just like us. Of course your body expects to have all of the parts it started with. Of course your brain would assume it was merely misinterpreting signals when suddenly a limb was missing. The alternative was too awful to consider.

It never occurred to me that the body could experience phantom pain from a part of the body that was never supposed to exist. As soon as my epidural line was pulled five days post-op, I started having severe sporadic pain where my stoma used to be. It was distinct from the other pains – the burning in the lower colon, the sharpness in the rectum, the soreness near the incisions.

This was something different. It felt like when my body tried to pass stool through the stoma, but couldn’t because of an obstruction. It was the same exact same sensation. My body remembers the route of a path that should never have been there to begin with.

I lived 29 years without an ostomy. In the two years that I had it, I believed it was the best solution for me, and for most of that time, I believed that I would always have it. The only way to survive was a radical acceptance of this defect. I told myself that this was the best option for my body and I made myself believe it. I believed it so much that even my body was convinced.

I still have a wound where my stoma was. It is closing slowly. Mostly the pain is manageable; I know it will never really go away. Several times a day, I feel my body mimic the pressure of an obstruction behind the stoma, the twisting and lines of pain spiderwebbing into my lower back. The pain isn’t real, but my brain won’t believe it.

Phantom pain is notoriously resistant to pain medication. One of the better options is the use of psychological “tricks” to convince your body that it is still intact. I am thinking about how to do this. But I don’t know which version of my GI tract my brain thinks is real.

 

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.

 

References:

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.

The impossible things

I don’t remember the first time I was amazed at what my body could do, but a few episodes come immediately to mind. In 2007, my friend and I got lost while hiking in Norway near Bergen. We lost the moderate grade trail and instead found ourselves very carefully descending rock faces and hiking for several hours longer than expected. We had adequate food and water, decent weather and the benefit of a very late sunset, but almost twelve hours of physical exertion made for a long day.

When we got back to the hostel, it took almost an hour in a hot shower to get all the dirt off. We were exhausted. I crawled into bed and slept deeply, a narcotic, dreamless rest. Just before I fell asleep, I thought to myself that I couldn’t believe that I hadn’t injured myself.

In 2009, I fell through the floor of my attic, which was the ceiling of my front porch. I grabbed a beam as I fell and pulled myself up without hesitation. As I sat on the beam, remembering the image of my legs in the hole with my porch below, I was pretty impressed that I had managed to catch myself. I hit a different beam as I fell and had lots of bumps and bruises, including a huge one right at the top of my leg. In the bathroom mirror, it looked like a black smile.  I was otherwise fine.

There are other moments. The first time I did crow pose. The day I ran a 5K. The several 3-day walks in which I walked sixty miles in three days. Actual feats of physical prowess.

I can no longer do things like that. Maybe I will again someday, but right now, it would be impossible. Still, there are moments when my body amazes me.

I walked down to the harbor yesterday. After weeks of suffocating greyness, 35°F felt like spring. The world outside was thawing, liquid, burning bright with reflected light. I didn’t care how much pain I would be in tomorrow. I just wanted to be alive in a world that was finally thawing, even for a short time.

Boston Harbor was frozen. There were no waves. The water was motionless. Large white globes of ice hung suspended, a crystalline sheen atop the surface. It was otherworldly, and really very beautiful. By the time I got home, I was in a massive amount of pain from the muscular strain of staying stable on ice and snow. I spent last night in bed on muscle relaxers with my heated blanket gathered against the small of my back.

Today the pain is worse and the world is once again encased in ice. But I am renewed in the knowledge that sometimes, my body is still capable of impossible things. I may never climb a mountain again, but in the brief reprieve from a legendary winter, my body walked to the ocean and saw the world doing impossible things, too.

 

Boston Harbor

 

MCAS: Pain

Pain is an unfortunate fact of life with MCAS. Muscle fatigue and weakness are common complaints, but myositis and rhabdomyolysis are rare. Some patients have elevated creatine kinase and/or aldolase, but have no related symptoms.

Bone pain is frequently reported with MCAS. Osteopenia and osteoporosis are common findings. Focal osteosclerosis is also sometimes found, but less frequently. Joints are often painful, which can lead to diagnoses of osteoarthritis, seronegative rheumatoid arthritis, fibromyalgia and polymyalgia rheumatica. Pain can migrate and is often poorly localized. Patients often feel pain in joints, bones and soft tissues, sometimes inconsistently.

Mast cells have been implicated in several pain disorders. Chronic lower back pain has been hypothesized to be related to mast cell activation for over a decade. Complex regional pain syndrome Type I, formerly known as reflex sympathetic dystrophy (RSD) and reflex neurovascular dystrophy (RND), is the most painful long term condition described. It is marked by neurogenic inflammation (nervous system swelling), sensitization of pain receptors and circulatory problems that cause swelling and color changes. It can affect any part of the body. Mast cells have been linked to the inflammatory response seen in CRPS patients.

Neurons with noradrenaline, serotonin and opioidergic receptors inhibit transmission of pain signals. (This is why taking opiates works for pain – it binds to these opioidergic receptors and suppresses the pain signals.) In the spinal cord, pain signals from the peripheral pathways meet up with the spinal pain signals to send to the brain. Here is where molecules like GABA, opioids made in the body and serotonin control pain transmission.

In chronic pain, serotonin acts to amplify the peripheral pain signals instead of suppress them. Increased serotonin levels and mast cell counts are found in many patients with chronic abdominal pain. About 95% of serotonin in the body is found in the peritoneal cavity, which explains the chronic pain many people feel in this region. Mediators released from colon biopsies in IBS patients were proven to excite the local nerves and activate pain receptors. Serotonin is one of these mediators.

Some antidepressants are known to affect serotonin secretion from mast cells. In particular, tricyclic antidepressants inhibit serotonin release in a dose dependent manner at higher concentrations. Clomipramine was seen to be the most effective, with amitriptyline and doxepin inhibiting release of serotonin and histamine at higher doses. All three were found to affect both uptake and reuptake of serotonin by mast cells and therefore lowering the relative concentration of serotonin in the local environment.

MCAS pain is often difficult to treat with typical pain medications. Antihistamines and cromolyn should be used to manage pain where possible. For bone related pain, bisphosphonates are usually effective. There is some data to suggest hydroxyurea can help manage pain in MCAS patients.

 

References:

Xinning Li, MD; Keith Kenter, MD; Ashley Newman, BS; Stephen O’Brien, MD, MBA. Allergy/ Hypersensitivity Reactions as a Predisposing Factor to Complex Regional Pain Syndrome I in Orthopedic Patients. Orthopedics 2014: Volume 37 · Issue 3: e286-e291

Giovanni Barbara, et al. Mast Cell-Dependent Excitation of Visceral-Nociceptive Sensory Neurons in Irritable Bowel Syndrome. Gastroenterology Volume 132, Issue 1, January 2007, Pages 26–37.

Ferjan, F. Erjavec . Changes in histamine and serotonin secretion from rat peritoneal mast cells caused by antidepressants. Inflammation Research 1996, Volume 45, Issue 3, pp 141-144.

Barbara, V. Stanghellini, R. De Giorgio et al. Activated mast cells in proximity to colonic nerves correlate with abdominal pain in irritable bowel syndrome. Gastroenterology, vol. 126, no. 3, pp. 693–702, 2004.

Barbara, B. Wang, V. Stanghellini et al. Mast cell-dependent excitation of visceral-nociceptive sensory neurons in irritable bowel syndrome. Gastroenterology, vol. 132, no. 1, pp. 26–37, 2007.

Afrin, Lawrence B. Diagnosis, presentation and management of mast cell activation syndrome. 2013. Mast cells.

The memory of pain


“It’s so hard to forget pain, but it’s even harder to remember sweetness.  We have no scar to show for happiness.  We learn so little from peace.”  -Chuck Palahniuk, Diary
I’m a medical scientist.  At a conference a few years ago, one of the doctors was recounting a phenomenon we are all familiar with – the patient who swears that their current illness is the worst they have ever had.  It’s not, though.  “They just forget how bad it is,” he surmised.  They are lucky, these normal people.  They get sick a few times a year, so infrequently that the light of their health overwhelms those dark spots. 
I’m not like that, and I don’t think I ever have been.  I’m very grateful for my good days, but when I look back over the landscape for the last few years, that’s not what stands out.  I remember the happiness and enjoyment of those days, but not the physical feeling.  It’s hard to commit the sensation of “less” or “better” to memory; it is merely a fact I can regurgitate when my doctors ask me.  It evokes nothing in me physically. 
I remember pain more than anything else.  I feel like this says something about me as a person, but it’s true.  I spend a lot of time with my pain, after all; it changes and evolves, but never really leaves.  It started in my hands and feet, arthritis that I feel as soon as I open my eyes.  Then my other joints, stiff and sore with motion, throbbing when still.  My lower back, that feels like a seam along which my body will break when I bend.  My lower abdomen, my entire GI tract that burns and twists.  The throbbing in the long bone of my thigh, the twisting in my chest.  The bright red sunburn of anaphylaxis all over my skin.  I have become skilled at cataloguing it, at knowing what is normal and what is new. 
Whether I like it or not, I have learned a lot from my pain.  It has forced me to prioritize my life, to actively pursue the things I want and to eschew what I don’t.  It has forced me to really want things, or to forget about them.  My pain makes me tired and irritable; it guarantees I only spend time with those people who are deeply important to me.  I never do anything just for the sake of doing it.  And in many ways, that is a blessing.
It used to bother me when people talked about being grateful for their illnesses.  I’m not grateful for my illness.  I would rather not have it.  But I like my life, and I like who I am, and my disease is part of the shaping forces responsible.  I am more empathetic now, more organized.  I expect less of people and am let down less.  I deal with disappointment better.  I accept that I cannot do everything I want to.  I suppose I’m grateful for those things, even if I would rather have come to these realizations by another route. 
Sometimes I’ll have a couple good days in a row and I think to myself, maybe this is when it gets better.  Maybe this is when things start steadily improving.  Maybe this is when my pain subsides and I get back the life I had where I could stay out late and drink alcohol and run a 5K and do yoga every day. 
Realistically, that’s never going to happen.  I will never be healthier than I am now; there is too much damage.  But every once in a while it feels like a possibility, and it doesn’t erase the memory of the pain, but it does soften it, just a little.