Dermatitis, Allergic Contact: A contact dermatitis due to allergic sensitization to various substances. These substances subsequently produce inflammatory reactions in the skin of those who have acquired hypersensitivity to them as a result of prior exposure.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.Dermatitis, Occupational: A recurrent contact dermatitis caused by substances found in the work place.Dermatitis, Atopic: A chronic inflammatory genetically determined disease of the skin marked by increased ability to form reagin (IgE), with increased susceptibility to allergic rhinitis and asthma, and hereditary disposition to a lowered threshold for pruritus. It is manifested by lichenification, excoriation, and crusting, mainly on the flexural surfaces of the elbow and knee. In infants it is known as infantile eczema.Dermatitis, Irritant: A non-allergic contact dermatitis caused by prolonged exposure to irritants and not explained by delayed hypersensitivity mechanisms.Dermatitis: Any inflammation of the skin.Dermatitis, Contact: A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms.Irritants: Drugs that act locally on cutaneous or mucosal surfaces to produce inflammation; those that cause redness due to hyperemia are rubefacients; those that raise blisters are vesicants and those that penetrate sebaceous glands and cause abscesses are pustulants; tear gases and mustard gases are also irritants.Oxazolone: Immunologic adjuvant and sensitizing agent.Dinitrofluorobenzene: Irritants and reagents for labeling terminal amino acid groups.Dermatitis Herpetiformis: Rare, chronic, papulo-vesicular disease characterized by an intensely pruritic eruption consisting of various combinations of symmetrical, erythematous, papular, vesicular, or bullous lesions. The disease is strongly associated with the presence of HLA-B8 and HLA-DR3 antigens. A variety of different autoantibodies has been detected in small numbers in patients with dermatitis herpetiformis.Cosmetics: Substances intended to be applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance without affecting the body's structure or functions. Included in this definition are skin creams, lotions, perfumes, lipsticks, fingernail polishes, eye and facial makeup preparations, permanent waves, hair colors, toothpastes, and deodorants, as well as any material intended for use as a component of a cosmetic product. (U.S. Food & Drug Administration Center for Food Safety & Applied Nutrition Office of Cosmetics Fact Sheet (web page) Feb 1995)Dermatitis, Toxicodendron: An allergic contact dermatitis caused by exposure to plants of the genus Toxicodendron (formerly Rhus). These include poison ivy, poison oak, and poison sumac, all plants that contain the substance urushiol, a potent skin sensitizing agent. (From Dorland, 27th ed)Local Lymph Node Assay: The local lymph node assay (LLNA) is an alternative method for the identification of chemicals that have the ability to cause skin sensitization and allergic contact dermatitis. Endpoints have been established so fewer animals are required and less painful procedures are used.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.PhenylenediaminesFacial DermatosesDermatitis, Seborrheic: A chronic inflammatory disease of the skin with unknown etiology. It is characterized by moderate ERYTHEMA, dry, moist, or greasy (SEBACEOUS GLAND) scaling and yellow crusted patches on various areas, especially the scalp, that exfoliate as dandruff. Seborrheic dermatitis is common in children and adolescents with HIV INFECTIONS.Haptens: Small antigenic determinants capable of eliciting an immune response only when coupled to a carrier. Haptens bind to antibodies but by themselves cannot elicit an antibody response.Nickel: A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.Skin Cream: A water-soluble medicinal preparation applied to the skin.Allergens: Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Perfume: A substance, extract, or preparation for diffusing or imparting an agreeable or attractive smell, especially a fluid containing fragrant natural oils extracted from flowers, woods, etc., or similar synthetic oils. (Random House Unabridged Dictionary, 2d ed)Lawsonia Plant: A plant genus of the family LYTHRACEAE that is the source of henna and has cytotoxic activity.Laboratory Chemicals: Chemicals necessary to perform experimental and/or investigative procedures and for the preparation of drugs and other chemicals.Desonide: A nonfluorinated corticosteroid anti-inflammatory agent used topically for DERMATOSES.InkGloves, Protective: Coverings for the hands, usually with separations for the fingers, made of various materials, for protection against infections, toxic substances, extremes of hot and cold, radiations, water immersion, etc. The gloves may be worn by patients, care givers, housewives, laboratory and industrial workers, police, etc.Hand DermatosesEczema: A pruritic papulovesicular dermatitis occurring as a reaction to many endogenous and exogenous agents (Dorland, 27th ed).Epoxy Resins: Polymeric resins derived from OXIRANES and characterized by strength and thermosetting properties. Epoxy resins are often used as dental materials.Construction Industry: The aggregate business enterprise of building.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.Picryl Chloride: A hapten that generates suppressor cells capable of down-regulating the efferent phase of trinitrophenol-specific contact hypersensitivity. (Arthritis Rheum 1991 Feb;34(2):180).Ear, External: The outer part of the hearing system of the body. It includes the shell-like EAR AURICLE which collects sound, and the EXTERNAL EAR CANAL, the TYMPANIC MEMBRANE, and the EXTERNAL EAR CARTILAGES.Croton Oil: Viscous, nauseating oil obtained from the shrub Croton tiglium (Euphorbaceae). It is a vesicant and skin irritant used as pharmacologic standard for skin inflammation and allergy and causes skin cancer. It was formerly used as an emetic and cathartic with frequent mortality.Administration, Topical: The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.Pruritus: An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief.AcrylatesPetrolatum: A colloidal system of semisolid hydrocarbons obtained from PETROLEUM. It is used as an ointment base, topical protectant, and lubricant.Langerhans Cells: Recirculating, dendritic, antigen-presenting cells containing characteristic racket-shaped granules (Birbeck granules). They are found principally in the stratum spinosum of the EPIDERMIS and are rich in Class II MAJOR HISTOCOMPATIBILITY COMPLEX molecules. Langerhans cells were the first dendritic cell to be described and have been a model of study for other dendritic cells (DCs), especially other migrating DCs such as dermal DCs and INTERSTITIAL DENDRITIC CELLS.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.Tattooing: The indelible marking of TISSUES, primarily SKIN, by pricking it with NEEDLES to imbed various COLORING AGENTS. Tattooing of the CORNEA is done to colorize LEUKOMA spots.Hair Dyes: Dyes used as cosmetics to change hair color either permanently or temporarily.Preservatives, Pharmaceutical: Substances added to pharmaceutical preparations to protect them from chemical change or microbial action. They include ANTI-BACTERIAL AGENTS and antioxidants.Keratinocytes: Epidermal cells which synthesize keratin and undergo characteristic changes as they move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell.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.Administration, Cutaneous: The application of suitable drug dosage forms to the skin for either local or systemic effects.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.Hypersensitivity: Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.Dermatitis, Perioral: A papular eruption of unknown etiology that progresses to residual papular erythema and scaling usually confined to the area of the mouth, and almost exclusively occurring in young women. It may also be localized or extend to involve the eyelids and adjacent glabella area of the forehead (periocular dermatitis). (Dorland, 28th ed)Dermatitis, Exfoliative: The widespread involvement of the skin by a scaly, erythematous dermatitis occurring either as a secondary or reactive process to an underlying cutaneous disorder (e.g., atopic dermatitis, psoriasis, etc.), or as a primary or idiopathic disease. It is often associated with the loss of hair and nails, hyperkeratosis of the palms and soles, and pruritus. (From Dorland, 27th ed)Chromium: A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.Contact Lenses: Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)Radiodermatitis: A cutaneous inflammatory reaction occurring as a result of exposure to ionizing radiation.Mice, Inbred BALB CDisease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Immunoglobulin E: An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Dermatologic Agents: Drugs used to treat or prevent skin disorders or for the routine care of skin.Emollients: Oleagenous substances used topically to soothe, soften or protect skin or mucous membranes. They are used also as vehicles for other dermatologic agents.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.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.Digital Dermatitis: Highly contagious infectious dermatitis with lesions near the interdigital spaces usually in cattle. It causes discomfort and often severe lameness (LAMENESS, ANIMAL). Lesions can be either erosive or proliferative and wart-like with papillary growths and hypertrophied hairs. DICHELOBACTER NODOSUS and TREPONEMA are the most commonly associated causative agents for this mixed bacterial infection disease.