Jump to content

Mast cell activation syndrome

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by PolarYukon (talk | contribs) at 17:50, 21 December 2017 (→‎See also: add histamine intolerance). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Not to be confused with Mastocytosis.
Mast cell activation syndrome

Mast cell activation syndrome (MCAS) is one type of mast cell activation disorder (MCAD), and is an immunological condition in which mast cells inappropriately and excessively release chemical mediators, resulting in a range of chronic symptoms, sometimes including anaphylaxis or near-anaphylaxis attacks.[1][2][3] Primary symptoms include cardiovascular, dermatological, gastrointestinal, neurological and respiratory problems.[2]

Unlike mastocytosis, another type of MCAD, where patients have an abnormally increased number of mast cells, patients with MCAS have a normal number of mast cells that do not function properly and are defined as "hyperresponsive".[2] MCAS is still a poorly understood condition and is a current topic of research.[4]

MCAS is often found in patients with Ehlers–Danlos syndrome (EDS) and postural orthostatic tachycardia syndrome (POTS).[5] It is also found in subset groups of patients with common variable immunodeficiency (CVID)[6] and Lyme disease.[7]

Symptoms and triggers

MCAS is a condition that affects multiple systems, generally in an inflammatory manner. Symptoms typically wax and wane over time, varying in severity and duration. Many signs and symptoms are the same as those for mastocytosis, because both conditions result in too many mediators released by mast cells.[8] It has many overlapping characteristics with recurrent idiopathic anaphylaxis, although there are distinguishing symptoms, specifically hives and angioedema.[9]

Common symptoms include:[4][10]

  • Dermatological
    • flushing
    • easy bruising
    • either a reddish or a pale complexion
    • itchiness
  • Cardiovascular
    • lightheadedness, dizziness, presyncope, syncope
  • Gastrointestinal
    • diarrhea, cramping, intestinal discomfort
    • nausea, vomiting
    • swallowing, throat tightness
  • Psychological & Neurological
    • brain fog, short term memory dysfunction, difficulty with recalling words
    • headaches, migraines
  • Respiratory
    • congestion, coughing, wheezing
  • Vision/Eyes
    • ocular discomfort, conjunctivitis
  • Constitutional
    • general fatigue and malaise
    • food, drug, and chemical intolerances (especially fragrances)
    • sense of being cold all the time
  • Musculoskeletal
    • osteoporosis and osteopenia (including young patients)
  • Anaphylaxis If too many mediators are spilt into a patient's system, they may also experience anaphylaxis, which primarily includes: difficulty breathing, itchy hives, flushing or pale skin, feeling of warmth, weak and rapid pulse, nausea, vomiting, diarrhea, dizziness and fainting.

Symptoms can be caused or worsened by triggers, which vary widely and are patient-specific. Common triggers include:[10]

  • specific foods and drinks (especially alcohol, and high-histamine content foods)
  • temperature extremes
  • airborne smells including perfumes or smoke
  • exercise or exertion
  • emotional stress
  • hormonal changes, particularly during adolescence, pregnancy and women's menstrual cycles

Causes

There are no known causes, but the condition appears to be inherited in some patients.[5] Symptoms of MCAS are caused by excessive chemical mediators inappropriately released by mast cells. Mediators include leukotrienes and histamines. The condition may be mild until exacerbated by stressful life events, or symptoms may develop and slowly trend worse with time.[4][5]

Diagnosis

MCAS is often difficult to identify due to the heterogeneity of symptoms and the "lack of flagrant acute presentation."[10] The condition can also be difficult to diagnose, especially since many of the numerous symptoms may be considered "vague". Patients often see many different specialties due to the inherent multisystem nature of the condition, and do not get diagnosed until a holistic view is taken by a diagnostician.[8] Lack of awareness of MCAS by many medical professionals is currently a hurdle to proper diagnosis.

"Although different diagnostic criteria are published, a commonly used strategy to diagnose patients is to use all three of the following:
  1. Symptoms consistent with chronic/recurrent mast cell release:
    Recurrent abdominal pain, diarrhea, flushing, itching, nasal congestion, coughing, chest tightness, wheezing, lightheadedness (usually a combination of some of these symptoms is present)
  2. Laboratory evidence of mast cell mediator (elevated serum tryptase, N-methyl histamine, prostaglandin D2 or 11-beta- prostaglandin F2 alpha, leukotriene E4 and others)
  3. Improvement in symptoms with the use of medications that block or treat elevations in these mediators"[4]

The World Health Organization has not published diagnostic criteria.

Treatment

Common pharmacological treatments include:

Fillers, binders and dyes in many medications are often the culprit in causing reactions, not necessarily the active agent, so alternative formulations and compounding pharmacies should be considered.[8]

Lifestyle changes may also be needed. Avoidance of triggers is important. It should be emphasized that MCAS patients can potentially react to any new exposure, including food, drink, medication, microbes and smoke via inhalation, ingestion or touch.[8]

A low histamine diet and other elimination diets can be useful in identifying foods that trigger or worsen symptoms. Many MCAS patients already have high histamine levels, so ingesting foods with high histamine or histamine liberators can worsen many symptoms such as vasodilation that causes faintness and palpitations.

Prognosis

There is no cure for MCAS. For most, symptoms wax and wane, but many can experience a general worsening trend over time. Lifespan for those with MCAS appears to be normal, but quality of life can range from mild discomfort to severely impaired.[8] Some patients are impaired enough to be disabled and unable to work.

Epidemiology

MCAS is a relatively new diagnosis, being unnamed until 2007, and is believed to be very under-diagnosed.[8] New findings are revealing that MCAS is much more prevalent than previously thought.

History

It has been suggested in the literature for decades; however diagnostic criteria have been proposed only in 2010.[2] The condition was first recognized in 1991, and finally named in 2007.[8]

See also

References

  1. ^ Valent P (2013). "Mast Cell Activation Syndromes: Definition and Classification". Allergy. 68 (4): 417–24. doi:10.1111/all.12126. PMID 23409940.
  2. ^ a b c d Akin C, Valent P, Metcalfe DD (2010). "Mast cell activation syndrome: Proposed diagnostic criteria". J. Allergy Clin. Immunol. 126: 1099–104.e4. doi:10.1016/j.jaci.2010.08.035. PMC 3753019. PMID 21035176.
  3. ^ Akin C (2015). "Mast Cell Activation Syndromes Presenting as Anaphylaxis". Immunology and Allergy Clinics of North America. 35 (2): 277–85. doi:10.1016/j.iac.2015.01.010.
  4. ^ a b c d White, Andrew, Dr. "A Tale of Two Syndromes – POTS and MCAS". The Dysautonomia Dispatch. Dysautonomia International, 17 Feb. 2015. Web. 12 Oct. 2015. <http://www.dysautonomiainternational.org/blog/wordpress/a-tale-of-two-syndromes-pots-and-mcas/>.
  5. ^ a b c Milner, Joshua, Dr. "Research Update: POTS, EDS, MCAS Genetics." 2015 Dysautonomia International Conference & CME. Washington DC. Dysautonomia International Research Update: POTS, EDS, MCAS Genetics. Web. <https://vimeo.com/142039306>.
  6. ^ Szczawinska-Poplonyk A. "An Overlapping Syndrome of Allergy and Immune Deficiency in Children". Journal of Allergy. 2012: 1–9. doi:10.1155/2012/658279.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  7. ^ Talkington J, Nickell SP (Mar 1999). "Borrelia burgdorferi Spirochetes Induce Mast Cell Activation and Cytokine Release". Infect Immun. 67 (3): 1107–1115. PMC 96436. PMID 10024550.
  8. ^ a b c d e f g h i Afrin, Lawrence B. "A Concise, Practical Guide to Diagnostic Assessment for Mast Cell Activation Disease." WJH World Journal of Hematology 3.1 (2014): 155-232. Web. <https://www.novapublishers.com/catalog/product_info.php?products_id=42603>.
  9. ^ a b c d e Frieri M (2015). "Mast Cell Activation Syndrome". Clin Rev Allergy Immunol. doi:10.1007/s12016-015-8487-6. PMID 25944644.
  10. ^ a b c Afrin, Lawrence, Dr. "Presentation, Diagnosis, and Management of Mast Cell Activation Syndrome." Mast Cells: Phenotypic Features, Biological Functions and Role in Immunity. Nova Science, 2013. 155-232. Web. <https://www.novapublishers.com/catalog/product_info.php?products_id=42603>.
  11. ^ Finn DF, Walsh JJ (2013). "Twenty-first century mast cell stabilizers". Br. J. Pharmacol. 170 (1): 23–37. doi:10.1111/bph.12138. PMC 3764846. PMID 23441583. A diverse range of mast cell stabilizing compounds have been identified in the last decade from; natural, biological and synthetic sources to drugs already in clinical uses for other indications. Although in many cases, the precise mode of action of these molecules is unclear, all of these substances have demonstrated mast cell stabilization activity and therefore may have potential therapeutic use in the treatment of allergic and related diseases where mast cells are intrinsically involved.Table 1: Naturally occurring mast cell stabilizers
  12. ^ Weng Z, Zhang B, Asadi S, Sismanopoulos N, Butcher A, Fu X, Katsarou-Katsari A, Antoniou C, Theoharides TC (2012). "Quercetin is more effective than cromolyn in blocking human mast cell cytokine release and inhibits contact dermatitis and photosensitivity in humans". PLoS ONE. 7 (3): e33805. doi:10.1371/journal.pone.0033805. PMC 3314669. PMID 22470478.{{cite journal}}: CS1 maint: unflagged free DOI (link)

Recent medical reviews on MCAS:

Retrieved from "https://en.wikipedia.org/w/index.php?title=Mast_cell_activation_syndrome&oldid=816488039"