In medicine, mastocytosis is a group of rare disorders of both children and adults caused by the presence of too many mast cells (mastocytes) in a person's body. Medicine on the Web NLM (National Library of Medicine, contains resources for patients and healthcare professionals) Virtual Hospital (digital health sciences library by the University of Iowa) Online Medical Dictionary Collection of links to free medical resources Categories: Medicine | Health ... A rare disease has such a low prevalence in a population that a doctor in a busy general practice would not expect to see more than one case a year. ... A mast cell (or mastocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. ...

Symptoms

Chemicals released by mast cells cause changes in the immune system leading to typical allergy symptoms such as itching, abdominal cramping, and even anaphylaxis (shock from allergic or immune causes). A mast cell (or mastocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. ... The immune system is the system of specialised cells and organs that protect an organism from outside biological influences. ... An allergy or Type I hypersensitivity is an immune malfunction whereby a persons body is hypersensitised to react immunologically to typically nonimmunogenic substances. ... An itch (Latin: pruritus) is a sensation felt on an area of skin that makes a person or animal want to scratch it. ... Anaphylaxis is a severe and rapid systemic allergic reaction to a trigger substance, called an allergen. ... In medicine, shock (hypoperfusion) is a life-threatening medical emergency characterized by inability of the body to supply enough oxygen to meet tissue requirements. ...

When too many mast cells exist in a person's body, the additional chemicals can cause

• bone or muscle pain;
• Abdominal discomfort;
• Nausea and vomiting;
• Stomach ulcers;
• Diarrhea;
• Skin lesions;
• Episodes of very low blood pressure and faintness;
• Shock.

Bone Pain- Bone pain is generally referred to as having pain within the affected bone. ... Myalgia means muscle pain and is a symptom of many diseases and disorders. ... According to the International Association for the Study of Pain (IASP), one should distinguish between pain and nociception. ... Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. ... Nausea (Greek Ναυτεία) is the sensation of unease and discomfort in the stomach with an urge to vomit. ... Vomiting (or emesis) is the forceful expulsion of the contents of ones stomach through the mouth. ... Peptic ulcer is usually a non-malignant ulcer of the stomach (called gastric ulcer) or duodenum (called duodenal ulcer). ... Diarrhea (AmE) or diarrhoea (CwE) is a condition in which the sufferer has frequent and watery or loose bowel movements (from the ancient Greek word διαρροή = leakage; lit. ... Dermatology (from Greek derma, skin) is a branch of medicine dealing with the skin, its structure, functions, and diseases, as well as its appendages (nails, hair, sweat glands). ... In physiology and medicine, hypotension refers to an abnormally low blood pressure. ... Syncope has two distinct and apparantly unrelated meanings, one in linguistics and another in medicne. ... In medicine, shock (hypoperfusion) is a life-threatening medical emergency characterized by inability of the body to supply enough oxygen to meet tissue requirements. ...

Diagnosis

Doctors can diagnose urticaria pigmentosa (cutaneous mastocytosis, see below) by seeing the characteristic lesions which are dark-brown and fixed. A small skin sample (biopsy) may help confirm the diagnosis. Urticaria Pigmentosa is the most common form of cutaneous mastocytosis. ... A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. ...

By taking a biopsy from a different organ, such as the bone marrow, the doctor can diagnose systemic mastocytosis. Using special techniques on a bone marrow sample, the doctor looks for an increase in mast cells. Another sign of this disorder is high levels of certain mast-cell chemicals and proteins in a person's blood and sometimes in the urine. A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. ... Bone marrow is the tissue comprising the center of large bones. ... Blood tests are laboratory tests done on blood to gain an appreciation of disease states and the function of organs. ... Urine is liquid waste excreted by the kidneys and eventually expelled from the body in a process known as urination. ...

Classification

The presence of too many mast cells, or mastocytosis, can occur in a variety of forms. Most cases are cutaneous (confined to the skin only).

There are several forms of cutaneous mastocytosis. The most common is called urticaria pigmentosa (UP). It mostly affects children. Telangiectasia Macularis Eruptiva Perstans (TMEP) is a much rarer form of cutaneous mastocytosis that affects adults. Urticaria Pigmentosa is the most common form of cutaneous mastocytosis. ...

Systemic mastocytosis involves the internal organs, usually in addition to involving the skin. Mast cells collect in various tissues and can affect organs such as the liver, spleen, lymph nodes, and bone marrow. The liver is an organ in vertebrates, including humans. ... The spleen is a ductless, vertebrate gland that is not necessary for life but is closely associated with the circulatory system, where it functions in the destruction of old red blood cells and removal of other debris from the bloodstream, and also in holding a reservoir of blood. ... Structure of the lymph node. ... Bone marrow is the tissue comprising the center of large bones. ...

Pathophysiology

Mast cells are located in connective tissue, including the skin, the linings of the stomach and intestine, and other sites. They may play an important role in helping defend these tissues from disease. By releasing chemical "alarms" such as histamine, mast cells attract other key players of the immune defense system to areas of the body where they are needed. A mast cell (or mastocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. ... Connective tissue is any type of biological tissue with an extensive extracellular matrix and often serves to support, bind together, and protect organs. ... Model of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system; which is composed of a layer of tissues that protect underlying muscles and organs. ... Histamine is a biogenic amine chemical involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. ... The immune system is the system of specialised cells and organs that protect an organism from outside biological influences. ...

Mast cells seem to have other roles as well. Because they gather together around wounds, mast cells may play a part in wound healing. For example, the typical itching you feel around a healing scab may be caused by histamine released by mast cells. Researchers also think mast cells may have a role in the growth of blood vessels (angiogenesis). No one with too few or no mast cells has been found, which indicates to some scientists that we may not be able to survive with too few mast cells. A wound is a physical trauma where the skin is torn, cut or punctured. ... Histamine is a biogenic amine chemical involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. ... The arterial system The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... Angiogenesis is the physiological process involving the formation of new blood vessels from pre-existing vessels. ...

Mast cells express a cell surface receptor termed c-kit (CD117), which is the receptor for scf (stem cell factor). In laboratory studies, scf appears to be important for the proliferation of mast cells, and inhibiting the tyrosine kinase receptor with imatinib (see below) may reduce the symptoms of mastocytosis. Cluster of differentiation (CD) molecules are markers on the cell surface, as recognized by specific sets of antibodies, used to identify the cell type, stage of differentiation and activity of a cell. ... In biochemistry, a receptor is a protein on the cell membrane or within the cytoplasm that binds to a specific factor (a ligand), such as a neurotransmitter, hormone, or other substance, and initiates the cellular response to the ligand. ... Tyrosine kinases are a subclass of protein kinase, see there for the principles of protein phosphorylation A tyrosine kinase (EC 2. ... Imatinib is a drug used to treat certain types of cancer. ...

History

Scientists first described urticaria pigmentosa in 1869. Systemic mastocytosis was first reported by scientists in 1936. 1869 is a common year starting on Friday (link will take you to calendar). ... 1936 was a leap year starting on Wednesday (link will take you to calendar). ...

Epidemiology

No one is sure how many people have either type of mastocytosis, but mastocytosis generally has been considered to be an "orphan disease" (orphan diseases affect 200,000 or fewer people in the United States). Mastocytosis, however, often may be misdiagnosed, and occur more frequently than assumed. A rare disease has such a low prevalence in a population that a doctor in a busy general practice would not expect to see more than one case a year. ...

Treatment

There is currently no cure for mastocytosis. However, there are a number of medicines to help treat the symptoms of mastocytosis:

• Antihistamines block receptors targeted by histamine released from mast cells. Both H1 and H2 blockers may be helpful.
• Leukotriene antagonists block receptors targeted by leukotrienes released from mast cells.
• Mast cell stabilizers help prevent mast cells from releasing their chemical contents. Cromolyn Sodium Oral Solution (Gastrocrom® / Cromoglicate) is the only medicine specifically approved by the FDA for the treatment of mastocytosis.
• Aspirin directly triggers mast cell degranulation. An alternative strategy to mast cell stabilizers is to use daily aspirin to always keep mast cells highly degranulated, thereby leaving them with less histamine to release at inopportune times.
• Proton pump inhibitors help reduce production of gastric acid, which is often increased in patients with mastocytosis. Excess gastric acid can harm the stomach, esophagus, and small intestine.
• Epinephrine constricts blood vessels and opens airways to maintain adequate circulation and ventilation when excessive mast cell degranulation has caused Anaphylaxis.
• Albuterol and other beta-2 agonists open airways which can constrict in the presence of histamine.
• Corticosteroids can be used topically, inhaled, or systemically to reduce inflamation associated with mastocytosis.
• Immunotherapy (Allergy Shots) may rarely be beneficial to select patients with mastocytosis. The benefits of the shots should be weighed against the substantially increased risk of severe and potentially fatal anaphylaxis triggered by the shots themselves.
• Antidepressants are an important and often overlooked tool in the treatment of mastocytosis. The stress and physical discomfort of any chronic disease may increase the likelihood of a patient developing depression. Depression and other neurological symptoms have been noted in mastocytosis (see Rogers et al). Some antidepressants such as doxepin are themselves potent antihistamines and can help relieve physical as well as cognitive symptoms.

In rare cases in which mastocytosis is cancerous or associated with a blood disorder, the patient may have to use steroids and/or chemotherapy. The novel agent imatinib (Glivec® or Gleevec®) has been found to be effective in certain types of mastocytosis. An antihistamine is a drug which serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions, through action at the histamine receptor. ... Cromoglicate (INN) (also referred to as cromolyn (USAN) or cromoglycate (former BAN)) is a mast cell stabilizing drug, and is commonly marketed as the sodium salt sodium cromoglicate. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Proton pump inhibitors are a group of drugs whose main action is pronounced and long-lasting reduction of gastric acid production. ... Epinephrine (INN) or adrenaline (BAN) is a hormone and a neurotransmitter. ... Anaphylaxis is a severe and rapid systemic allergic reaction to a trigger substance, called an allergen. ... Salbutamol (INN) or albuterol (USAN) is a short-acting β2-adrenergic receptor agonist used for the relief of bronchospasm in conditions such as asthma and COPD. It is marketed by the Allen & Hanburys respiratory division of GlaxoSmithKline under the trade name Ventolin. ... In physiology, corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. ... Immunotherapy is a form of medical treatment based upon the concept of modulating the immune system to achieve a therapeutic goal In the context of allergies, immunotherapy can be beneficial. ... An antidepressant is a medication designed to treat or alleviate the symptoms of clinical depression; antidepressants function generally by interacting with the neurotransmitters (signalling chemicals) in the brain believed to influence mood. ... Look up Depression on Wiktionary, the free dictionary Depression may refer to one of the following: Clinical depression, a medical condition which includes decreased interest in pleasurable activities Depression (mood), an everyday term for a sad mood Depression (geology), a sunken or depressed geological formation Depression (economics) is a more... Doxepin, is a tricyclic antidepressant // History Doxepin was synthesized by Stach and Spingler from the German drug manufacturer C. F. Boehringer & Söhne GmbH in Mannheim. ... A steroid is a lipid characterized by a carbon skeleton with four fused rings. ... Chemotherapy is the use of chemical substances to treat disease. ... Imatinib is a drug used to treat certain types of cancer. ...

There are clinical trials currently underway testing stem cell transplants as a form of treatment.

There are support groups for persons suffering from mastocytosis. Involvement can be emotionally therapuetic for some patients.

Research

National Institute of Allergy and Infectious Diseases (NIAID) scientists have been studying and treating patients with mastocytosis for several years at the National Institutes of Health (NIH) Clinical Center. National Institute of Allergy and Infectious Diseases (NIAID) is a component of the National Institutes of Health (NIH), which is an agency of the United States Department of Health and Human Services. ... The National Institutes of Health is an institution of the United States government which focuses on medical research. ...

Some of the most important research advances for this rare disorder include improved diagnosis of mast cell disease and identification of growth factors and genetic mechanisms responsible for increased mast cell production. Researchers are currently evaluating approaches to improve ways to treat mastocytosis.

Scientists also are focusing on identifying disease-associated mutations (changes in genes). NIH scientists have identified some mutations, which may help researchers understand the causes of mastocytosis, improve diagnosis, and develop better treatments.

Sources

• Based on an informative page by the National Institute of Allergy and Infectious Diseases (NIAID).
• Rogers MP, Bloomingdale K, Murawski BJ, Soter NA, Reich P, Austen KF. Mixed organic brain syndrome as a manifestation of systemic mastocytosis. Psychosom Med 1986;48:437-47. PMID 3749421.
• Ellis DL. Treatment of telangiectasia macularis eruptiva perstans with the 585-nm flashlamp-pumped dye laser. Dermatol Surg 1996;22:33-7. PMID 8556255.
• Godt O, Proksch E, Streit V, Christophers E. Short- and long-term effectiveness of oral and bath PUVA therapy in urticaria pigmentosa and systemic mastocytosis. Dermatology 1997;195:35-9. PMID 9267734.

External links

• Mastocytosis Society, Inc.
• Mastocytosis