Glossary of mast cell related terms: A-E

Allergic march: the progressive accumulation of atopic conditions beginning in the first year of life; usually atopic dermatitis, allergic rhinitis, asthma, food allergy

Anaphylaxis: a rapidly progressing allergic reaction that involves multiple organ systems; can be fatal

Angioedema: Swelling caused when fluid leaves the bloodstream and becomes trapped between the deep dermis and subcutaneous tissue.

Anticholinergic: blocking the molecule acetylcholine from sending signals in the nervous system.  Many medications are anticholinergic, which can cause many side effects.

Ascites: free fluid in the abdomen; a form of third spacing

Aggressive systemic mastocytosis (ASM): a form of systemic mastocytosis in which mast cells invade organs, causing damage and dysfunction; diagnosed when a person meeting the criteria for SM has one or more C finding, criteria that indicate organ damage caused by mast cells

Asthma: inflammation of the airways causing swelling, narrowing and extra mucus production; can be allergic in nature

Atopy: tendency of a person to develop allergic diseases like asthma

Autoimmune disease: a disease caused when the immune system attacks healthy cells; mast cell diseases are not autoimmune diseases

Autonomic nervous system: a part of the nervous system that controls many involuntary functions of the body, including digestion.  It is composed of both the parasympathetic nervous system and the sympathetic nervous system.

B finding: criteria that indicate SM is progressing towards mast cells invading organs and damaging them; if 2 or more are present, smouldering systemic mastocytosis (SSM) is diagnosed

Biphasic anaphylaxis: Second episode of anaphylaxis symptoms after resolution

Bradykinin: a mediator released by mast cells that causes inflammation, pain and swelling

CD117: another name for CKIT receptor, found normally on the outside of mast cells

CD2: a marker not usually found on the outside of mast cells; an indicator of systemic mastocytosis; a cell adhesion molecule

CD25: a marker not usually found on the outside of mast cells; an indicator of systemic mastocytosis; part of a receptor for IL-2

CD34: a marker normally found on the outside of cells that become mast cells, and on new mast cells

Chronic urticaria: hives lasting longer than six weeks; can include angioedema

Circadian rhythm: the body’s internal clock

CKIT: a receptor on the outside of mast cells that binds stem cell factor, telling mast cells to stay alive and make more cells; is often mutated in systemic mastocytosis

Complement : a system of many small proteins circulating in the blood that can attack infectious agent ; can also cause angioedema

Cortisol : a steroid hormone produced by the adrenal glands ; critical in regulating stress response

COX : cyclooxygenase; enzymes that produce prostaglandins

Cutaneous mastocytosis (CM): infiltration of the skin by excessive mast cells.  The most common type of mastocytosis.

D816V/CKIT+: a specific mutation at codon 816 of the CKIT gene that causes the CKIT receptor to be misshapen so that mast cells get inappropriate signals to stay alive and keep making more cells

Darier’s sign: a wheal and flare response elicited by touching mast cell lesions; caused by histamine release

Desensitization: the elimination of the body’s allergic response to something

Diffuse cutaneous mastocytosis (DCM): The most severe presentation of cutaneous mastocytosis.  Lesions cover much of the body and may blister or bleed.

Deconditioning: when the body becomes acclimated to less physical stress and becomes less able to function properly under normal conditions.

Degranulation: the release of mediators stored in granules inside a cell; mast cell degranulation contributes to immune response as well as symptom profile in mast cell disease and anaphylaxis

Delayed food-induced anaphylaxis to meat: An IgE mediated reaction to beef, pork or lamb that occurs several hours after eating; caused by a tick bite inducing production of antibodies to carbohydrate a-gal.

Dysautonomia: fundamental dysfunction of the autonomic nervous system; there are many types, including POTS

Ehlers-Danlos Syndrome (EDS): a group of conditions caused by hypermobility and/or known genetic mutation affecting production of connective tissue components; Hypermobility EDS is seen disproportionately in the mast cell community

Edema: swelling; excess fluid trapped in tissues

Eicosanoid: the molecular class that includes prostaglandins and leukotrienes

Eosinophilia: elevation of eosinophils in the blood

Eosinophilic esophagitis: infiltration of the esophagus by eosinophils

Eosinophilic GI disease: IgE and delayed cell mediated reactions to foods caused by overactive eosinophils, affecting the GI tract.

Eosinophils: a granulocyte functioning similar to mast cells; mast cells and eosinophils can activate each other

Epinephrine: a hormone used to treat anaphylaxis

Exercise intolerance: diminished ability or inability to perform physical exercise; can be caused by a number of medical conditions