An acute hypersensitivity reaction due to exposure to a previously encountered ANTIGEN. The reaction may include rapidly progressing URTICARIA, respiratory distress, vascular collapse, systemic SHOCK, and death.

An evanescent cutaneous reaction occurring when antibody is injected into a local area on the skin and antigen is subsequently injected intravenously along with a dye. The dye makes the rapidly occurring capillary dilatation and increased vascular permeability readily visible by leakage into the reaction site. PCA is a sensitive reaction for detecting very small quantities of antibodies and is also a method for studying the mechanisms of immediate hypersensitivity.

Gastrointestinal disturbances, skin eruptions, or shock due to allergic reactions to allergens in food.

An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).

Immunologically mediated adverse reactions to medicinal substances used legally or illegally.

Instruments or technological means of communication that reach large numbers of people with a common message: press, radio, television, etc.

Bites and stings inflicted by insects.

A group of LEUKOTRIENES; (LTC4; LTD4; and LTE4) that is the major mediator of BRONCHOCONSTRICTION; HYPERSENSITIVITY; and other allergic reactions. Earlier studies described a "slow-reacting substance of ANAPHYLAXIS" released from lung by cobra venom or after anaphylactic shock. The relationship between SRS-A leukotrienes was established by UV which showed the presence of the conjugated triene. (From Merck Index, 11th ed)

Allergic reaction to wheat that is triggered by the immune system.

Allergic reaction to peanuts that is triggered by the immune system.

Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the BASOPHILS, mast cells contain large amounts of HISTAMINE and HEPARIN. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the STEM CELL FACTOR.

The secretion of histamine from mast cell and basophil granules by exocytosis. This can be initiated by a number of factors, all of which involve binding of IgE, cross-linked by antigen, to the mast cell or basophil's Fc receptors. Once released, histamine binds to a number of different target cell receptors and exerts a wide variety of effects.

Epicutaneous or intradermal application of a sensitizer for demonstration of either delayed or immediate hypersensitivity. Used in diagnosis of hypersensitivity or as a test for cellular immunity.

A vascular reaction of the skin characterized by erythema and wheal formation due to localized increase of vascular permeability. The causative mechanism may be allergy, infection, or stress.

Administration of a vaccine to large populations in order to elicit IMMUNITY.

An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.

Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).

Use of marketing principles also used to sell products to consumers to promote ideas, attitudes and behaviors. Design and use of programs seeking to increase the acceptance of a social idea or practice by target groups, not for the benefit of the marketer, but to benefit the target audience and the general society.

Encouraging consumer behaviors most likely to optimize health potentials (physical and psychosocial) through health information, preventive programs, and access to medical care.

Granular leukocytes characterized by a relatively pale-staining, lobate nucleus and cytoplasm containing coarse dark-staining granules of variable size and stainable by basic dyes.

Spasmodic contraction of the smooth muscle of the bronchi.

Agents that are used to treat allergic reactions. Most of these drugs act by preventing the release of inflammatory mediators or inhibiting the actions of released mediators on their target cells. (From AMA Drug Evaluations Annual, 1994, p475)

The process of losing secretory granules (SECRETORY VESICLES). This occurs, for example, in mast cells, basophils, neutrophils, eosinophils, and platelets when secretory products are released from the granules by EXOCYTOSIS.

Venoms from the superfamily Formicoidea, Ants. They may contain protein factors and toxins, histamine, enzymes, and alkaloids and are often allergenic or immunogenic.

The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.

Immunosuppression by the administration of increasing doses of antigen. Though the exact mechanism is not clear, the therapy results in an increase in serum levels of allergen-specific IMMUNOGLOBULIN G, suppression of specific IgE, and an increase in suppressor T-cell activity.

Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.

A chromone complex that acts by inhibiting the release of chemical mediators from sensitized mast cells. It is used in the prophylactic treatment of both allergic and exercise-induced asthma, but does not affect an established asthmatic attack.

Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.

An anthranilic acid derivative with analgesic properties used for the relief of all types of pain.

Allergic reaction to products containing processed natural rubber latex such as rubber gloves, condoms, catheters, dental dams, balloons, and sporting equipment. Both T-cell mediated (HYPERSENSITIVITY, DELAYED) and IgE antibody-mediated (HYPERSENSITIVITY, IMMEDIATE) allergic responses are possible. Delayed hypersensitivity results from exposure to antioxidants present in the rubber; immediate hypersensitivity results from exposure to a latex protein.

A chemically diverse group of substances produced by various tissues in the body that cause slow contraction of smooth muscle; they have other intense but varied pharmacologic activities.

Drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists. Classical antihistaminics block the histamine H1 receptors only.

A mode of communication concerned with inducing or urging the adoption of certain beliefs, theories, or lines of action by others.

Hypersensitivity reactions which occur within minutes of exposure to challenging antigen due to the release of histamine which follows the antigen-antibody reaction and causes smooth muscle contraction and increased vascular permeability.

Education that increases the awareness and favorably influences the attitudes and knowledge relating to the improvement of health on a personal or community basis.

A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.

An albumin obtained from the white of eggs. It is a member of the serpin superfamily.

A plant genus of the FABACEAE family known for the seeds used as food.

Swelling involving the deep DERMIS, subcutaneous, or submucosal tissues, representing localized EDEMA. Angioedema often occurs in the face, lips, tongue, and larynx.

An anthelmintic used primarily as the citrate in the treatment of filariasis, particularly infestations with Wucheria bancrofti or Loa loa.

Venoms obtained from Apis mellifera (honey bee) and related species. They contain various enzymes, polypeptide toxins, and other substances, some of which are allergenic or immunogenic or both. These venoms were formerly used in rheumatism to stimulate the pituitary-adrenal system.

Organized services to administer immunization procedures in the prevention of various diseases. The programs are made available over a wide range of sites: schools, hospitals, public health agencies, voluntary health agencies, etc. They are administered to an equally wide range of population groups or on various administrative levels: community, municipal, state, national, international.

A live attenuated virus vaccine of chick embryo origin, used for routine immunization of children and for immunization of adolescents and adults who have not had measles or been immunized with live measles vaccine and have no serum antibodies against measles. Children are usually immunized with measles-mumps-rubella combination vaccine. (From Dorland, 28th ed)

A highly contagious infectious disease caused by MORBILLIVIRUS, common among children but also seen in the nonimmune of any age, in which the virus enters the respiratory tract via droplet nuclei and multiplies in the epithelial cells, spreading throughout the MONONUCLEAR PHAGOCYTE SYSTEM.

Drugs that bind to and activate adrenergic receptors.

Drugs that interrupt transmission of nerve impulses at the skeletal neuromuscular junction. They can be of two types, competitive, stabilizing blockers (NEUROMUSCULAR NONDEPOLARIZING AGENTS) or noncompetitive, depolarizing agents (NEUROMUSCULAR DEPOLARIZING AGENTS). Both prevent acetylcholine from triggering the muscle contraction and they are used as anesthesia adjuvants, as relaxants during electroshock, in convulsive states, etc.

Substances found in PLANTS that have antigenic activity.

Skin tests in which the sensitizer is injected.

A genus of nematodes of the superfamily ASCARIDOIDEA whose species usually inhabit the intestine.

A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.

Venoms from animals of the phylum Arthropoda. Those most investigated are from scorpions and spiders of the class Arachnidae and from ant, bee, and wasp families of the Insecta order Hymenoptera. The venoms contain protein toxins, enzymes, and other bioactive substances and may be lethal to man.

A family of neutral serine proteases with TRYPSIN-like activity. Tryptases are primarily found in the SECRETORY GRANULES of MAST CELLS and are released during mast cell degranulation.

Allergic reaction to tree nuts that is triggered by the immune system.

Specific molecular sites on the surface of B- and T-lymphocytes which combine with IgEs. Two subclasses exist: low affinity receptors (Fc epsilon RII) and high affinity receptors (Fc epsilon RI).

Knowledge, attitudes, and associated behaviors which pertain to health-related topics such as PATHOLOGIC PROCESSES or diseases, their prevention, and treatment. This term refers to non-health workers and health workers (HEALTH PERSONNEL).

Antibodies, especially IGE, that bind to tissue of the same species so that ANTIGENS induce release of HISTAMINE and other vasoactive agents. HYPERSENSITIVITY is the clinical manifestation.

A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION.

An extensive order of highly specialized insects including bees, wasps, and ants.

A potent mast cell degranulator. It is involved in histamine release.

Studies designed to assess the efficacy of programs. They may include the evaluation of cost-effectiveness, the extent to which objectives are met, or impact.

Substances that are recognized by the immune system and induce an immune reaction.

A plant genus of the family POLYGONACEAE that is used as an EDIBLE GRAIN. Although the seeds are used as cereal, the plant is not one of the cereal grasses (POACEAE).

The transmission and reception of electric impulses or signals by means of electric waves without a connecting wire, or the use of these waves for the wireless transmission of electric impulses into which sound is converted. (From Webster's 3d)

An ergot derivative that is a congener of LYSERGIC ACID DIETHYLAMIDE. It antagonizes the effects of serotonin in blood vessels and gastrointestinal smooth muscle, but has few of the properties of other ergot alkaloids. Methysergide is used prophylactically in migraine and other vascular headaches and to antagonize serotonin in the carcinoid syndrome.

The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.

An in vitro test used in the diagnosis of allergies including drug hypersensitivity. The allergen is added to the patient's white blood cells and the subsequent histamine release is measured.

The transmission and reproduction of transient images of fixed or moving objects. An electronic system of transmitting such images together with sound over a wire or through space by apparatus that converts light and sound into electrical waves and reconverts them into visible light rays and audible sound. (From Webster, 3rd ed)