T.r.u.e. Test Thin-layer Rapid Use Patch Test

Nickel Sulfate (Position 1):

Nickel sulfate hexahydrate (purity ≥98.5%) is used to formulate this patch. The active allergenic component is nickel. The gel vehicle is hydroxypropyl cellulose. The product is formulated to contain 200 mcg/cm2 of nickel sulfate hexahydrate, which corresponds to 36 mcg of nickel per patch. Nickel is one of the most common metals in the environment and is found in most metal and metal-plated objects.

Wool Alcohols (Lanolin) (Position 2):

Wool alcohols, USP are a natural product obtained from the fleece of sheep. This allergen is a highly complex mixture of alcohols containing cholesterol, lanosterol, agnosterol, and their dihydro derivatives as well as straight and branched chain aliphatic alcohols. The active allergenic component has not been identified. The gel vehicle is povidone. The product is formulated to contain 1000 mcg/cm2 of wool alcohols, which corresponds to 810 mcg of wool alcohols per patch. Wool alcohols are a common constituent of many ointments, creams, lotions, and soaps.

Neomycin Sulfate (Position 3):

Neomycin sulfate, USP an antibiotic drug substance, is used to formulate this patch. The gel vehicle is methylcellulose. The product is formulated to contain 230 mcg/cm2 of neomycin sulfate, which corresponds to 186 mcg of neomycin sulfate per patch. Neomycin is a common antibiotic found in topical antibiotic creams, lotions, ointments, eye drops, and ear drops.

Potassium Dichromate (Position 4):

Potassium dichromate (purity ≥98.5%) is used to formulate this patch. The active allergenic component is chromium. The gel vehicle is hydroxypropyl cellulose. The product is formulated to contain 23 mcg/cm2 of potassium dichromate, which corresponds to 6.7 mcg of chromium per patch. Chromium is found in cement, as well as in many industrial chemicals.

Caine Mix (Position 5):

Caine mix is composed of three drug substances: benzocaine, USP (purity ≥98.0); tetracaine hydrochloride, USP (purity ≥98.5); and dibucaine hydrochloride, USP (purity ≥97.0). The gel vehicle is povidone. The product is formulated to contain 630 mcg/cm2 of caine mix, which corresponds to 510 mcg of caine mix per patch (378 mcg of benzocaine, 66 mcg of tetracaine, and 66 mcg of dibucaine). Benzocaine, tetracaine, and dibucaine are found in many topical anesthetic medications.

Fragrance Mix (Position 6):

Fragrance mix is composed of eight substances: geraniol (purity ≥95%, identity of impurities unknown); cinnamaldehyde (purity ≥95%, contains trace amounts of cinnamyl alcohol); hydroxycitronellal (purity ≥95%, identity of impurities unknown); cinnamyl alcohol (purity ≥95%, identity of impurities unknown); eugenol, USP (purity ≥95%, identity of impurities unknown); isoeugenol (purity ≥88%, identity of impurities unknown); α-amylcinnamaldehyde (purity ≥90%, identity of impurities unknown); and oak moss. Oak moss, a dark green sticky paste, is a solvent extract of the lichen Evernia prunastri. The chemical composition is very complex. The acid fraction (95% of the extracted material) is made up of depsides including atranorin, evernic acid, usnic acid, chloratranorin, and degradation products of these depsides. Atranorin is suspected as a prime allergenic component, and its peak (measured with gas chromatography) is used to determine the amount of oak moss in the fragrance mix patch. The gel vehicles used in this patch are hydroxypropylcellulose and β-cyclodextrin. The product is formulated to contain 430 mcg/cm2 of fragrance mix, which corresponds to 348 mcg of fragrance mix per patch (approximately 70 mcg of geraniol, approximately 35 mcg of cinnamaldehyde, approximately 54 mcg of hydroxycitronellal, approximately 54 mcg of cinnamyl alcohol, approximately 35 mcg of eugenol, approximately 15 mcg of isoeugenol, approximately 15 mcg of α-amylcinnamaldehyde, and approximately 70 mcg of oak moss). The components of fragrance mix are commonly used in toiletries, fragrances, and flavorings.

Colophony (Position 7):

Colophony is produced from the resin of the pine trees Pinus massoniana and Pinus tabuliformis. It is translucent, pale yellow or brownish yellow, brittle, and glassy in appearance. Colophony consists of 75% to 85% resin acids, 10% neutral fractions (i.e., terpenes), with the remaining part oxidation products. Oxidation products of abietic acid and other resin acids have been identified as the active allergenic components. The ultraviolet absorbance measurement of one of the primary components, abietic acid, is used to quantify colophony. The gel vehicle is povidone. BHA and BHT are added in equal amounts of 0.05% as antioxidants. The product is formulated to contain 1200 mcg/cm2 of colophony, which corresponds to 972 mcg of colophony per patch. Colophony is found in adhesives, sealants, and pine oil cleaners.

Paraben Mix (Position 8):

Paraben mix contains the five ester derivatives of parahydroxybenzoic acid: methyl, USP; ethyl, USP; propyl, USP; butyl, USP; and benzyl parahydroxybenzoate in equal parts (purity of each derivative ≥ 98.0%). The gel vehicle is povidone. The product is formulated to contain 1000 mcg/cm2of paraben mix, which corresponds to 810 mcg of paraben mix per patch. The components of paraben mix can be found in cosmetics, dermatological creams, and paste bandages.

Negative Control (Position 9):

The negative control is an uncoated polyester patch.

Balsam of Peru (Position 10):

Balsam of peru is a resin from a South American tree, Myroxylon balsamum pereirae. The resin consists of a mixture of fragrances and other substances that have not all been identified. Balsam of peru patch content is measured by gas chromatography of its two major constituents, benzyl cinnamate and benzyl benzoate. Several components of Balsam of peru have been identified as allergens, including cinnamic acid, benzyl alcohol, and vanillin. The gel vehicle is povidone. This patch is formulated to contain 800 mcg/cm2 of Balsam of peru resin, which corresponds to 648 mcg of Balsam of peru resin per patch. This resin is found in many cosmetics and perfumes and is also used as a flavoring agent in cough syrups, lozenges, chewing gum, and candies.

Ethylenediamine Dihydrochloride (Position 11):

Ethylenediamine dihydrochloride (purity ≥98.5%) is used to formulate this patch. The active allergenic component is ethylenediamine. The gel vehicle is methylcellulose. The product is formulated to contain 50 mcg/cm2 of ethylenediamine dihydrochloride, which corresponds to 18 mcg of ethylenediamine per patch. Ethylenediamine is used as a stabilizer, emulsifier, and preservative in topical fungicides, antibiotic creams, eye drops, and nose drops.

Cobalt Dichloride (Position 12):

Cobalt dichloride hexahydrate (purity ≥98.5%) is used to formulate this patch. The active allergenic component is cobalt. The gel vehicle is hydroxypropyl cellulose. The product is formulated to contain 20 mcg/cm2 of cobalt dichloride hexahydrate, which corresponds to 4 mcg of cobalt per patch. Cobalt is found in metal-plated objects and costume jewelry.

p-tert-Butylphenol Formaldehyde Resin (Position 13):

p-tert-Butylphenol formaldehyde resin (purity ≥95%) is used to formulate this patch. The active allergenic components have been identified as p-tert-butylphenol formaldehyde and numerous other compounds. The gel vehicle is hydroxypropyl cellulose. The product is formulated to contain 45 mcg/cm2 of p-tert-butylphenol formaldehyde resin, which corresponds to 36 mcg of p-tert-butylphenol formaldehyde resin per patch. This resin is found in many waterproof glues used in the leather goods, furniture, and shoe industries.

Epoxy Resin (Position 14):

Epoxy resin, a clear viscous liquid, is used to formulate this patch. It consists of 75% to 85% diglycidylether of bisphenol A, the active allergenic component, which is a monomer used for the preparation of polymer epoxy resins. The remaining part consists of the dimer and the trimer. The gel vehicle is hydroxypropyl cellulose. This patch is formulated to contain 50 mcg/cm2 of epoxy resin, which corresponds to 32 mcg of diglycidylether of bisphenol A per patch. This resin is found in adhesives, surface coatings, and paints.

Carba Mix (Position 15):

Carba mix contains three chemicals used to stabilize rubber products: diphenylguanidine (purity ≥96%), zincdibutyldithiocarbamate (purity ≥96%), and zincdiethyldithiocarbamate (purity ≥96%) in equal parts. The gel vehicle is hydroxypropyl cellulose. The product is formulated to contain 250 mcg/cm2 of carba mix, which corresponds to 203 mcg of carba mix per patch. These chemical stabilizers and accelerators are found in many rubber products, pesticides, and some glues.

Black Rubber Mix (Position 16):

Black rubber mix contains the antioxidant and antiozonate chemicals N-isopropyl-N'-phenyl paraphenylenediamine (purity ≥95%), N-cyclohexyl-N'-phenyl paraphenylenediamine (purity ≥90%), and N, N'-diphenyl paraphenylenediamine (purity ≥90%) in the ratio 2:5:5. The gel vehicle is povidone. The product is formulated to contain 75 mcg/cm2 of black rubber mix, which corresponds to 61 mcg of black rubber mix per patch. The components of black rubber mix are found in almost all black rubber products, such as tires, handles, and hoses.

Cl+ Me- Isothiazolinone (MCI/MI) (Position 17):

Cl+ Me- Isothiazolinone is an antibacterial preservative that consists of two active ingredients, 5-chloro-2-methyl-4-isothiazolin-3-one (1.05% to 1.25% w/w) and 2-methyl-4-isothiazolin-3-one (0.25% to 0.40% w/w) in a 3:1 ratio at a concentration of 1.5% in aqueous magnesium salts. The gel vehicle is povidone. The product is formulated to contain 4 mcg/cm2 of Cl+ Me- iso-thiazolinone, which corresponds to 3 mcg of Cl+ Me- isothiazolinone per patch. This preservative is found in many shampoos, creams, lotions, and other skin care products.

Quaternium-15 (Q-15) (Position 18):

Quaternium-15, 1-(3-chloroallyl)-3,5,7,-triaza-1-azonium-adamantane chloride (purity ≥94%), is a preservative. The gel vehicle is hydroxypropyl cellulose. The product is formulated to contain 100 mcg/cm2 of Quaternium-15, which corresponds to 81 mcg of Quaternium-15 per patch. This preservative is found in creams, lotions, shampoos, soaps, and other cosmetics and skin care products.

Methyldibromo Glutaronitrile (MDBGN) (Position 19):

Methyldibromo Glutaronitrile, 1,2-Dibromo-2,4-dicyanobutane (purity ≥95%), is a component of the preservative Euxyl K400. The gel vehicle is povidone. The patch is formulated to contain 5 mcg/cm2 of methyldibromo glutaronitrile, which corresponds to 4 mcg of methyldibromo glutaronitrile per patch. Methyldibromo glutaronitrile is commonly used in cosmetic and personal care products such as body creams, facial and hand lotions, sun screens, baby lotions, shower gels, ultrasonic gel, toilet paper, shampoos, and massage oils. It is also found in cutting oils, drilling oils, glues, and coolants.

p-Phenylenediamine (Position 20):

p-Phenylenediamine (purity ≥97.5%), a blue-black aniline dye, is used to formulate this patch. The gel vehicle is povidone. The product is formulated to contain 80 mcg/cm2 of p-phenylenediamine, which corresponds to 65 mcg of p-phenylenediamine per patch. This dye is found most often in permanent and semipermanent hair dyes.

Formaldehyde (Position 21):

Formaldehyde is released from the proallergen N-hydroxymethyl succinimide, which is cleaved into succinimide and formaldehyde when it comes in contact with the transepidermal water on the surface of the skin. Formaldehyde is the active allergenic compound. The content of formaldehyde in the proallergen is 22.1% to 24.1%. The gel vehicle is povidone with sodium bicarbonate and sodium carbonate. The product is formulated to contain 180 mcg/cm2 of formaldehyde, which corresponds to 146 mcg of formaldehyde per patch. Formaldehyde is found in many building materials and plastic industries.

Mercapto Mix (Position 22):

Mercapto mix is composed of three chemical accelerators that are benzothiazole sulfenamide derivatives. N-cyclohexylbenzothiazyl-sulfenamide (purity ≥85%), dibenzothiazyl disulfide (purity ≥97%), and morpholinylmercaptobenzothiazole (purity ≥85%) are present in equal parts. The gel vehicle is povidone. The product is formulated to contain 75 mcg/cm2 of mercapto mix, which corresponds to 61 mcg of mercapto mix per patch. This group of chemicals is found in many rubber products, such as shoes, gloves, and elastics.

Thimerosal (Position 23):

Thimerosal, USP (purity ≥97%) is a preservative that contains mercury. The gel vehicle is povidone. The product is formulated to contain 7 mcg/cm2 of thimerosal, which corresponds to 6 mcg of thimerosal per patch. Thimerosal is found in some cosmetics, nose drops, eardrops, and vaccines.

Thiuram Mix (Position 24):

Thiuram mix is composed of four substances in equal parts: tetramethylthiuram monosulfide (purity ≥95%, contains small amounts of tetramethylthiuram disulfide); tetramethylthiuram disulfide (purity ≥95%, contains small amounts of tetramethylthiuram monosulfide); disulfiram, USP (tetraethylthiuram disulfide, purity ≥98.0%); and dipentamethylenethiuram disulfide (purity ≥95%, impurities unknown). The components of thiuram mix can chemically interact, resulting in the formation of mixed disulfides. Thiuram monosulfides and disulfides are the active allergens. The gel vehicle is povidone. The product is formulated to contain 25 mcg/cm2 of thiuram mix, which corresponds to 20 mcg of thiuram mix per patch (5 mcg of tetramethylthiuram monosulfide, 5 mcg of tetramethylthiuram disulfide, 5 mcg of disulfiram, and 5 mcg of dipentamethylenethiuram disulfide). These antimicrobial, accelerator, and antioxidant substances are found in many rubber products.

Diazolidinyl Urea (DU) (Germall® II) (Position 25):

Diazolidinyl urea is a complex mixture. The gel vehicle is povidone. The product is formulated to contain 550 mcg/cm2 of diazolidinyl urea, which corresponds to 446 mcg of diazolidinyl urea per patch. Diazolidinyl urea is a preservative found in cosmetics.

Quinoline Mix (Position 26):

Quinoline mix is composed of two chemical germicides. Clioquinol, USP (purity ≥93.0%) and clorquinaldol (purity ≥95%), which are present in equal parts. The product is formulated to contain 190 mcg/cm2of quinoline mix, which corresponds to 154 mcg of quinoline mix per patch. The gel vehicle is povidone. Quinolines are found in paste bandages, medicated creams, and ointments.

Tixocortol-21-Pivalate (TIX) (Position 27):

Tixocortol-21-pivalate (purity ≥95%) is a corticosteroid. The gel vehicle is povidone. The product is formulated to contain 3 mcg/cm2 of tixocortol-21-pivalate, which corresponds to 2 mcg of tixocortol-21-pivalate per patch. Tixocortol-21-pivalate is found in some medical products. Patch testing with tixocortol-21-pivalate may be used to assist in the diagnosis of allergic contact dermatitis due to corticosteroids in Group A, based on the classification of topical corticosteroids by cross-reactivity.

Gold Sodium Thiosulfate (GST) (Position 28):

Gold sodium thiosulfate (purity ≥ 90%) is a fairly common sensitizer with elicitation of symptoms linked to gold in jewelry, occupational exposure to gold, previous rheumatoid arthritis treatment, dental restorations, and gold-plated intracoronary stents. The gel vehicle is hydroxypropyl cellulose and the product is formulated to contain 75 mcg/cm2 of gold sodium thiosulfate, which corresponds to 23 mcg of gold per patch.

Imidazolidinyl Urea (IMID) (Germall® 115) (Position 29):

Imidazolidinyl urea is a complex mixture. The gel vehicle is povidone. The product is formulated to contain 600 mcg/cm2 of imidazolidinyl urea, which corresponds to 486 mcg of imidazolidinyl urea per patch. Imidazolidinyl urea is a preservative found in cosmetics.

Budesonide (BUD) (Position 30):

Budesonide, USP (purity ≥98.0%) is a corticosteroid. The gel vehicle is povidone. The product is formulated to contain 1 mcg/cm2of budesonide, which corresponds to 0.8 mcg of budesonide per patch. Budesonide is found in topical medicinal and anti inflammatory products. Patch testing with budesonide may be used to assist in the diagnosis of allergic contact dermatitis due to corticosteroids in Group B and to certain esters in Group D, based on the classification of topical corticosteroids by cross-reactivity.

Hydrocortisone-17-Butyrate (H-17-B) (Position 31):

Hydrocortisone-17-butyrate, USP (purity ≥ 97.0%) is a mid-potent (Group D2) corticosteroid, most commonly used to treat inflammatory skin disease and psoriasis. The gel vehicle is povidone. The product is formulated to contain 20 mcg/cm2 of hydrocortisone-17-butyrate, which corresponds to 16 mcg of hydrocortisone-17-butyrate per patch. Hydrocortizone-17-butyrate is found in many topical over-the-counter (OTC) and prescription pharmaceuticals.

Mercaptobenzothiazole (Position 32):

Mercaptobenzothiazole (purity ≥98.5%) is a vulcanization accelerator used in rubber products. The gel vehicle is povidone. The product is formulated to contain 75 mcg/cm2 of mercaptobenzothiazole, which corresponds to 61 mcg of mercaptobenzothiazole per patch. This chemical is found in many rubber products, some adhesives, and is used as an industrial anticorrosive agent.

Bacitracin (Position 33):

Bacitracin, USP is an antibiotic used for postoperative and general wound care and is considered a frequent sensitizer. The gel vehicle is hydroxypropyl cellulose and the product is formulated to contain 600 mcg/cm2 of bacitracin which corresponds to 486 mcg of bacitracin per patch. Bacitracin is often a first-line topical remedy for cutaneous injuries and dermatoses as well as for many eye and ear disorders.

Parthenolide (Position 34):

Parthenolide (purity ≥ 95%) is a sesquiterpene lactone, which occurs naturally in thousands of plants including Daisies, Feverfew, and Magnolia. The gel vehicle is povidone and the product is formulated to contain 3 mcg/cm2 of parthenolide, which corresponds to 2 mcg of parthenolide per patch. Allergies to parthenolide occur frequently in gardeners and greenhouse employees, but non-occupational contact with plants and herbal teas containing sesquiterpenes also occurs.

Disperse Blue 106 (DB106) (Position 35):

Disperse blue 106 (purity ≥ 90%) is a commonly used thiazol-azoyl-p-phenylene diamine derivative dye used primarily in synthetic textiles and is a significant skin sensitization hazard. The product is formulated to contain 50 mcg/cm2 of disperse blue 106, which corresponds to 41 mcg of disperse blue 106 per patch. The gel vehicle is povidone. Together with Disperse blue 124, it has been determined to be the primary cause of textile dermatitis.

2-Bromo-2-nitropropane-1,3-diol (Bronopol) (Position 36):

2-Bromo-2-nitropropane-1,3-diol (purity ≥ 95%) is an antimicrobial agent commonly used as a preservative in many types of cosmetics, personal care products, and topical medications. The gel vehicle is povidone. The product is formulated to contain 250 mcg/cm2 of 2-Bromo-2-nitropropane-1,3-diol, which corresponds to 203 mcg of 2-Bromo-2-nitropropane-1,3-diol per patch.