Skin Tests: 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.Tuberculin Test: One of several skin tests to determine past or present tuberculosis infection. A purified protein derivative of the tubercle bacilli, called tuberculin, is introduced into the skin by scratch, puncture, or interdermal injection.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Intradermal Tests: Skin tests in which the sensitizer is injected.Latent Tuberculosis: The dormant form of TUBERCULOSIS where the person shows no obvious symptoms and no sign of the causative agent (Mycobacterium tuberculosis) in the SPUTUM despite being positive for tuberculosis infection skin test.Skin Aging: The process of aging due to changes in the structure and elasticity of the skin over time. It may be a part of physiological aging or it may be due to the effects of ultraviolet radiation, usually through exposure to sunlight.Skin DiseasesSkin Neoplasms: Tumors or cancer of the SKIN.Tuberculosis: Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.Hypersensitivity, Delayed: An increased reactivity to specific antigens mediated not by antibodies but by cells.Interferon-gamma Release Tests: The assay of INTERFERON-GAMMA released from lymphocytes after their exposure to a specific test antigen, to check for IMMUNOLOGIC MEMORY resulting from a previous exposure to the antigen. The amount of interferon-gamma released is usually assayed by an ENZYME-LINKED IMMUNOSORBENT ASSAY.Hypersensitivity, Immediate: 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.Tuberculin: A protein extracted from boiled culture of tubercle bacilli (MYCOBACTERIUM TUBERCULOSIS). It is used in the tuberculin skin test (TUBERCULIN TEST) for the diagnosis of tuberculosis infection in asymptomatic persons.BCG Vaccine: An active immunizing agent and a viable avirulent attenuated strain of Mycobacterium tuberculosis, var. bovis, which confers immunity to mycobacterial infections. It is used also in immunotherapy of neoplasms due to its stimulation of antibodies and non-specific immunity.Streptodornase and Streptokinase: A mixture of the enzymes (streptokinase and streptodornase) produced by hemolytic streptococci. It is used topically on surface lesions and by instillation in closed body cavities to remove clotted blood or fibrinous or purulent accumulations. It is also used as a skin test antigen in evaluating generalized cell-mediated immunodeficiency. (Dorland, 27th ed) EC 3.-.Drug Hypersensitivity: Immunologically mediated adverse reactions to medicinal substances used legally or illegally.Immunoglobulin E: An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Skin Physiological Phenomena: The functions of the skin in the human and animal body. It includes the pigmentation of the skin.Mycobacterium tuberculosis: A species of gram-positive, aerobic bacteria that produces TUBERCULOSIS in humans, other primates, CATTLE; DOGS; and some other animals which have contact with humans. Growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.Tuberculosis, Pulmonary: MYCOBACTERIUM infections of the lung.Skin Absorption: Uptake of substances through the SKIN.Radioallergosorbent Test: An in vitro allergen radioimmunoassay in which allergens are coupled to an immunosorbent. The coupled allergens bind the IgE in the sera of patients which in turn binds radioisotope-labeled anti-IMMUNOGLOBULIN E antibodies.HistoplasminHypersensitivity: Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.Allergens: Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Urticaria: 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.Skin Pigmentation: Coloration of the skin.Immunologic Tests: Immunologic techniques involved in diagnosis.Tuberculosis, Bovine: An infection of cattle caused by MYCOBACTERIUM BOVIS. It is transmissible to man and other animals.Basophil Degranulation Test: 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.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Anaphylaxis: 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.Erythema: Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of causes.Contact Tracing: Identification of those persons (or animals) who have had such an association with an infected person, animal, or contaminated environment as to have had the opportunity to acquire the infection. Contact tracing is a generally accepted method for the control of sexually transmitted diseases.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Interferon-gamma: The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.Skin, Artificial: Synthetic material used for the treatment of burns and other conditions involving large-scale loss of skin. It often consists of an outer (epidermal) layer of silicone and an inner (dermal) layer of collagen and chondroitin 6-sulfate. The dermal layer elicits new growth and vascular invasion and the outer layer is later removed and replaced by a graft.Mycobacterium bovis: The bovine variety of the tubercle bacillus. It is called also Mycobacterium tuberculosis var. bovis.Mites: Any arthropod of the subclass ACARI except the TICKS. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (MITE INFESTATIONS). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants.Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Food Hypersensitivity: Gastrointestinal disturbances, skin eruptions, or shock due to allergic reactions to allergens in food.Antigens, Fungal: Substances of fungal origin that have antigenic activity.Trichophytin: Antigens from the genus TRICHOPHYTON. Trichophytin has been used in studies of immunological responses to these dermatophytes.Guinea Pigs: 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.Coccidioidin: A sterile solution containing the by-products of growth products of COCCIDIOIDES IMMITIS, injected intracutaneously as a test for COCCIDIOIDOMYCOSIS.Skin Test End-Point Titration: A quantitative form of intradermal testing for the relative allergenicity of a substance. It is used to determine the amount of an allergen that will be tolerated in ALLERGEN IMMUNOTHERAPY.Leishmaniasis, Cutaneous: An endemic disease that is characterized by the development of single or multiple localized lesions on exposed areas of skin that typically ulcerate. The disease has been divided into Old and New World forms. Old World leishmaniasis is separated into three distinct types according to epidemiology and clinical manifestations and is caused by species of the L. tropica and L. aethiopica complexes as well as by species of the L. major genus. New World leishmaniasis, also called American leishmaniasis, occurs in South and Central America and is caused by species of the L. mexicana or L. braziliensis complexes.Leishmania braziliensis: A parasitic hemoflagellate of the subgenus Leishmania viannia that infects man and animals. It causes cutaneous (LEISHMANIASIS, CUTANEOUS), diffuse cutaneous (LEISHMANIASIS, DIFFUSE CUTANEOUS), and mucocutaneous leishmaniasis (LEISHMANIASIS, MUCOCUTANEOUS) depending on the subspecies of this organism. The sandfly, Lutzomyia, is the vector. The Leishmania braziliensis complex includes the subspecies braziliensis and peruviana. Uta, a form of cutaneous leishmaniasis in the New World, is caused by the subspecies peruviana.Respiratory Hypersensitivity: A form of hypersensitivity affecting the respiratory tract. It includes ASTHMA and RHINITIS, ALLERGIC, SEASONAL.Petasites: A plant genus of the family ASTERACEAE. Members contain SESQUITERPENES. The common name of sweet coltsfoot is similar to the common name for TUSSILAGO.Reagent Kits, Diagnostic: Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use.Transfer Factor: Factor derived from leukocyte lysates of immune donors which can transfer both local and systemic cellular immunity to nonimmune recipients.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Skin Diseases, Bacterial: Skin diseases caused by bacteria.Skin UlcerIsoniazid: Antibacterial agent used primarily as a tuberculostatic. It remains the treatment of choice for tuberculosis.Mass Chest X-Ray: X-ray screening of large groups of persons for diseases of the lung and heart by means of radiography of the chest.Antitubercular Agents: Drugs used in the treatment of tuberculosis. They are divided into two main classes: "first-line" agents, those with the greatest efficacy and acceptable degrees of toxicity used successfully in the great majority of cases; and "second-line" drugs used in drug-resistant cases or those in which some other patient-related condition has compromised the effectiveness of primary therapy.Desensitization, Immunologic: 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.Asthma: A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).Trichophyton: A mitosporic fungal genus and an anamorphic form of Arthroderma. Various species attack the skin, nails, and hair.Epidermis: The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of EPITHELIUM: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis).Leishmaniasis, Mucocutaneous: A disease characterized by the chronic, progressive spread of lesions from New World cutaneous leishmaniasis caused by species of the L. braziliensis complex to the nasal, pharyngeal, and buccal mucosa some time after the appearance of the initial cutaneous lesion. Nasal obstruction and epistaxis are frequent presenting symptoms.Dinitrochlorobenzene: A skin irritant that may cause dermatitis of both primary and allergic types. Contact sensitization with DNCB has been used as a measure of cellular immunity. DNCB is also used as a reagent for the detection and determination of pyridine compounds.Rhinitis: Inflammation of the NASAL MUCOSA, the mucous membrane lining the NASAL CAVITIES.Cell Migration Inhibition: Phenomenon of cell-mediated immunity measured by in vitro inhibition of the migration or phagocytosis of antigen-stimulated LEUKOCYTES or MACROPHAGES. Specific CELL MIGRATION ASSAYS have been developed to estimate levels of migration inhibitory factors, immune reactivity against tumor-associated antigens, and immunosuppressive effects of infectious microorganisms.Antigens: Substances that are recognized by the immune system and induce an immune reaction.Asymptomatic Infections: Infections that do not exhibit symptoms.Coccidioidomycosis: Infection with a fungus of the genus COCCIDIOIDES, endemic to the SOUTHWESTERN UNITED STATES. It is sometimes called valley fever but should not be confused with RIFT VALLEY FEVER. Infection is caused by inhalation of airborne, fungal particles known as arthroconidia, a form of FUNGAL SPORES. A primary form is an acute, benign, self-limited respiratory infection. A secondary form is a virulent, severe, chronic, progressive granulomatous disease with systemic involvement. It can be detected by use of COCCIDIOIDIN.Infectious Disease Transmission, Patient-to-Professional: The transmission of infectious disease or pathogens from patients to health professionals or health care workers. It includes transmission via direct or indirect exposure to bacterial, fungal, parasitic, or viral agents.Patch Tests: Skin tests in which the sensitizer is applied to a patch of cotton cloth or gauze held in place for approximately 48-72 hours. It is used for the elicitation of a contact hypersensitivity reaction.LeprominGambia: A republic in western Africa, constituting an enclave within SENEGAL extending on both sides of the Gambia River. Its capital is Banjul, formerly Bathurst.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Rhinitis, Allergic, Seasonal: Allergic rhinitis that occurs at the same time every year. It is characterized by acute CONJUNCTIVITIS with lacrimation and ITCHING, and regarded as an allergic condition triggered by specific ALLERGENS.Aspergillosis, Allergic Bronchopulmonary: Hypersensitivity reaction (ALLERGIC REACTION) to fungus ASPERGILLUS in an individual with long-standing BRONCHIAL ASTHMA. It is characterized by pulmonary infiltrates, EOSINOPHILIA, elevated serum IMMUNOGLOBULIN E, and skin reactivity to Aspergillus antigen.Rhinitis, Allergic, Perennial: Inflammation of the mucous membrane of the nose similar to that found in hay fever except that symptoms persist throughout the year. The causes are usually air-borne allergens, particularly dusts, feathers, molds, animal fur, etc.Latex Hypersensitivity: 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.Basophils: 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.Veterinary Medicine: The medical science concerned with the prevention, diagnosis, and treatment of diseases in animals.Silicotuberculosis: Pulmonary or extrapulmonary infection caused by MYCOBACTERIUM TUBERCULOSIS or nontuberculous mycobacteria in a patient with silicosis.Drug Eruptions: Adverse cutaneous reactions caused by ingestion, parenteral use, or local application of a drug. These may assume various morphologic patterns and produce various types of lesions.Skin Abnormalities: Congenital structural abnormalities of the skin.Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.Ethiopia: An independent state in eastern Africa. Ethiopia is located in the Horn of Africa and is bordered on the north and northeast by Eritrea, on the east by Djibouti and Somalia, on the south by Kenya, and on the west and southwest by Sudan. Its capital is Addis Ababa.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.False Positive Reactions: Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Leprosy: A chronic granulomatous infection caused by MYCOBACTERIUM LEPRAE. The granulomatous lesions are manifested in the skin, the mucous membranes, and the peripheral nerves. Two polar or principal types are lepromatous and tuberculoid.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Bronchial Provocation Tests: Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.Injections, Intradermal: The forcing into the skin of liquid medication, nutrient, or other fluid through a hollow needle, piercing the top skin layer.Mass Screening: Organized periodic procedures performed on large groups of people for the purpose of detecting disease.Health Personnel: Men and women working in the provision of health services, whether as individual practitioners or employees of health institutions and programs, whether or not professionally trained, and whether or not subject to public regulation. (From A Discursive Dictionary of Health Care, 1976)Staphylococcal Skin Infections: Infections to the skin caused by bacteria of the genus STAPHYLOCOCCUS.PeruTime Factors: Elements of limited time intervals, contributing to particular results or situations.Leishmania: A genus of flagellate protozoa comprising several species that are pathogenic for humans. Organisms of this genus have an amastigote and a promastigote stage in their life cycles. As a result of enzymatic studies this single genus has been divided into two subgenera: Leishmania leishmania and Leishmania viannia. Species within the Leishmania leishmania subgenus include: L. aethiopica, L. arabica, L. donovani, L. enrietti, L. gerbilli, L. hertigi, L. infantum, L. major, L. mexicana, and L. tropica. The following species are those that compose the Leishmania viannia subgenus: L. braziliensis, L. guyanensis, L. lainsoni, L. naiffi, and L. shawi.Hematologic Tests: Tests used in the analysis of the hemic system.Dust: Earth or other matter in fine, dry particles. (Random House Unabridged Dictionary, 2d ed)Cockroaches: Insects of the order Dictyoptera comprising several families including Blaberidae, BLATTELLIDAE, Blattidae (containing the American cockroach PERIPLANETA americana), Cryptocercidae, and Polyphagidae.Tinea: Fungal infection of keratinized tissues such as hair, skin and nails. The main causative fungi include MICROSPORUM; TRICHOPHYTON; and EPIDERMOPHYTON.Mycobacterium: A genus of gram-positive, aerobic bacteria. Most species are free-living in soil and water, but the major habitat for some is the diseased tissue of warm-blooded hosts.Dermatitis: Any inflammation of the skin.Coccidioides: A mitosporic fungal genus which causes COCCIDIOIDOMYCOSIS.Endemic Diseases: The constant presence of diseases or infectious agents within a given geographic area or population group. It may also refer to the usual prevalence of a given disease with such area or group. It includes holoendemic and hyperendemic diseases. A holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). A hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. (Last, A Dictionary of Epidemiology, 3d ed, p53, 78, 80)Leishmaniasis, Visceral: A chronic disease caused by LEISHMANIA DONOVANI and transmitted by the bite of several sandflies of the genera Phlebotomus and Lutzomyia. It is commonly characterized by fever, chills, vomiting, anemia, hepatosplenomegaly, leukopenia, hypergammaglobulinemia, emaciation, and an earth-gray color of the skin. The disease is classified into three main types according to geographic distribution: Indian, Mediterranean (or infantile), and African.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Triprolidine: Histamine H1 antagonist used in allergic rhinitis; ASTHMA; and URTICARIA. It is a component of COUGH and COLD medicines. It may cause drowsiness.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Dermatologic Surgical Procedures: Operative procedures performed on the SKIN.Skin Diseases, Viral: Skin diseases caused by viruses.Mycobacterium Infections: Infections with bacteria of the genus MYCOBACTERIUM.Skin Cream: A water-soluble medicinal preparation applied to the skin.BrazilWuchereria: A genus of filarial nematodes.Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Insect Bites and Stings: Bites and stings inflicted by insects.Lymphocytes: White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.Skin Physiological Processes: Biological activities and functions of the SKIN.Eczema: A pruritic papulovesicular dermatitis occurring as a reaction to many endogenous and exogenous agents (Dorland, 27th ed).Hair: A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.Passive Cutaneous Anaphylaxis: 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.Arthus Reaction: A dermal inflammatory reaction produced under conditions of antibody excess, when a second injection of antigen produces intravascular antigen-antibody complexes which bind complement, causing cell clumping, endothelial damage, and vascular necrosis.Occupational Diseases: Diseases caused by factors involved in one's employment.Mice, Hairless: Mutant strains of mice that produce little or no hair.Bacterial Proteins: Proteins found in any species of bacterium.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Mycobacterium leprae: A species of gram-positive, aerobic bacteria that causes LEPROSY in man. Its organisms are generally arranged in clumps, rounded masses, or in groups of bacilli side by side.Carcinoma, Basal Cell: A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)Bee Venoms: 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.Ultraviolet Rays: That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.Flour: Ground up seed of WHEAT.Anti-Allergic Agents: 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)Antigens, Plant: Substances found in PLANTS that have antigenic activity.Histamine Release: 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.Wasp Venoms: Venoms produced by the wasp (Vespid) family of stinging insects, including hornets; the venoms contain enzymes, biogenic amines, histamine releasing factors, kinins, toxic polypeptides, etc., and are similar to bee venoms.Dermis: A layer of vascularized connective tissue underneath the EPIDERMIS. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are SWEAT GLANDS; HAIR FOLLICLES; and SEBACEOUS GLANDS.Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Histoplasmosis: Infection resulting from inhalation or ingestion of spores of the fungus of the genus HISTOPLASMA, species H. capsulatum. It is worldwide in distribution and particularly common in the midwestern United States. (From Dorland, 27th ed)Alternaria: A mitosporic Loculoascomycetes fungal genus including several plant pathogens and at least one species which produces a highly phytotoxic antibiotic. Its teleomorph is Lewia.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Nasal Provocation Tests: Application of allergens to the nasal mucosa. Interpretation includes observation of nasal symptoms, rhinoscopy, and rhinomanometry. Nasal provocation tests are used in the diagnosis of nasal hypersensitivity, including RHINITIS, ALLERGIC, SEASONAL.DNA, Kinetoplast: DNA of kinetoplasts which are specialized MITOCHONDRIA of trypanosomes and related parasitic protozoa within the order KINETOPLASTIDA. Kinetoplast DNA consists of a complex network of numerous catenated rings of two classes; the first being a large number of small DNA duplex rings, called minicircles, approximately 2000 base pairs in length, and the second being several dozen much larger rings, called maxicircles, approximately 37 kb in length.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.False Negative Reactions: Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Neuromuscular Blocking Agents: 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.