Patch testing is a type of skin allergy testing that involves placing a test substance on a patient’s back to determine the types of allergens that cause skin rashes.
People with prolonged eczema that is suspected to be caused by contact allergies, people with chronic dermatitis, especially on the hands, feet, face, or eyelids, those who suffer from an unknown cause of dermatitis, people with eczema and worsening rash symptoms, patients with other types of skin diseases, such as atopic dermatitis, along with worsening conditions from having a contact allergic rash. People who suspect they may have an allergic reaction to an allergen should consult a doctor before treatment.
Patients should bring products or items suspected to cause allergies along with product packages and labels, such as cosmetics, soaps, skin creams, etc. Refrain from using steroids at least 2 weeks before the oral type test and 1 week before the skin test. Do not sunbathe or expose your back to the sun about 1 week before the test.
The doctor will place 31 test agents (or suspected causes of allergies) onto the test strip and place them on the patient’s back for 48 hours then wait for the skin to react. Then doctor will schedule a reading of the results. The patient must visit the doctor at least 2-3 times.
Throughout the test period, the patient must make sure not to wet their back with water or sweat by refraining from playing sports, attending saunas, etc. The patient may take antihistamines if the irritation is severe. At the end of the test, the doctor will inform which substances cause allergies and where would such substances be found either in the utensils or in certain products for the patient to avoid contact with such allergens.
| Allergens | Found in |
| 1. Potassium dichromate, chromium | Cement, concrete, stainless steel, plating with chrome alloys, corrosion inhibitors, chrome-tanning leather, green dyes, and metallic pigments; inks, and paints. Cosmetics; mascara, eyeliners, eye shadows (green), green tattoo, chromic surgical gut sutures, orthopedic and dental implants or prosthesis |
| 2. p-Phenylenediamine (PPD) | Permanent and semi-permanent hair dye, black henna, temporary black tattoo, hair dye shampoo, textile and fur dyes, photo developing agents, printing ink, black rubber industry. May cross-react with p-toluene diamine sulfate |
| 3. Thiuram mix | Manufacturing of natural and synthetic rubber; gloves, shoes, boots, swimwear, wetsuits, goggles, rubber band, racquet, and club handles. Medical equipment such as anesthesia equipment, gloves, and Antabuse Used in fungicides, and pesticides. May cross-react with carba mix. |
| 4. Neomycin | Topical antibiotic cream, ointment, lotion, eye/ ear medication, pet care and veterinary antibiotics. |
| 5. Cobalt | Nickel-plated objects (always contain cobalt), metal alloys, key metal clothing fasteners, costume jewelry; earrings, necklaces, eyelash curlers, cosmetics; eye shadow, used to produce blue colors in pottery, glass, porcelain, and enamel, blue printing ink, blue tattoo, vitamin B12 supplement, orthopedic prosthesis (Vitallium) and dental implant. |
| 6. Nickel | Nickel-plated objects, metal alloys, costume jewelry; earrings, necklaces, eyeglasses, coins, keys, metal clothing fasteners, needle, hair clips, paper clips, kitchen utensils, canned food/ drink; cosmetics, eye shadow, eyebrow pencils, pigment in cosmetic (color index 77489,77491, 77492, 77499); orthodontic and dental appliances. |
| 7. Colophony | Wood products, sawdust, wood fillers; glues and adhesives in medicated plaster, topical salves (e.g. Zam-Buk ). Coatings, polishes, and waxes; waxed thread. Cosmetics such as eyeliners, eye shadows, mascara, lipstick, and wax depilatories. Racquet and club handles, instrument rosin, Industrial lubricants and cutting fluids; soldering products. |
| 8. Paraben Mix | Preservatives in most cosmetics, soap, lotion, oral / hair care products, medicated cream, eye/ ear medication, hemorrhoid preparation, topical analgesic medication, pet care& grooming products. Preservatives in food and drink such as candy, jam, jelly, ketchup, and soft drinks. |
| 9.N-Isopropyl-N-Phenyl-4- phenylenediamine (IPPD) | Used as an antioxidant in the rubber industry (black rubber). Found in gloves, shoes, boots, stockings, motorcycle handles, tires, goggles, lubricating oils, and greases. |
| 10. Lanolin alcohol | Obtained from the wool of sheep. Used as an ointment base in cosmetic and pharmaceutical products such as medicated shampoos, moisturizers, sunscreens, lipsticks, makeup removers, foundations, hairsprays, and shaving creams. Found in pet care/ veterinary products, printing inks, polishes, leather, metal-working fluid including lubricants, and cutting fluid. |
| 11. Mercapto mix | Manufacturing of natural and synthetic rubber (butyl rubber, nitrile, or neoprene); gloves, boots, swimwear, wetsuits, goggles, rubber bands, ear- and headphones, masks, racquet and club handles, hoses, and tires. Medical equipment such as anesthesia equipment. |
| 12. Epoxy resin, Bisphenol A | Two-component adhesives, coatings, paints, and composite materials with a curing agent. Lightweight equipment, tennis racquets, skis, household glue, electrical insulation, dental bonding agents, and dental restorative materials. |
| 13. Peru Balsum | Fragrance in perfumes, cosmetics, deodorants, toothpaste, mouthwash, and shave lotions. Ingredient in medicinal products such as lozenges and tiger balm. Used for flavoring in food and drink, artificially baked goods, vanilla, candy, chewing gum, soft drinks including colas, flavored tea, gin, vermouth, citrus peel, marmalade, spices such as cloves, cinnamon, ketchup. Candles, incense, and essential oils. |
| 14.4-test-Butyphenolformaldehyde resin (PTBP) | Adhesives and glues in leather and rubber shoes, neoprene adhesives, photosensitive coatings, varnish and lacquer resins, cosmetics (e.g., deodorants, lip liner), construction materials such as laminated wood and plywood products, adhesives used on electrocardiograph monitoring electrodes. |
| 15.2-Hydroxyethyl methacrylate | UV inks, adhesives, lacquers, dental materials, and artificial nails. High-performance coatings for glass to guard against scratching and weathering, paint resins. |
| 16. Formaldehyde | Preservative in cosmetics, disinfectants, and antiseptics, industrial metalworking fluids and coolants, embalming and preserving fluids, durable press (wrinkle-resistant) fabrics, Pressed wood construction materials (particleboard, fiberboard, plywood), pesticide, paints, and polishes, Tobacco and cigarette smoke, smoke from wood/ coal/ charcoal fires. |
| 17. Fragrance Mix I | Contains cinnamic alcohol, cinnamaldehyde, hydroxycitronellal, amylcinnamaldehyde, geraniol, isoeugenol, eugenol, and oakmoss absolute. Used to add scent or flavor in perfume, cosmetics, soap, lotion, deodorant, toothpaste, air fresheners, scented candles, fabric softeners; food, and drink that contain citrus, clove, and cinnamon. |
| 18. Sesquiterpene lactone mix | Found in daisy, marigold, sunflower, chamomile, weeds, and chrysanthemums. Used in lotions, perfumes, cosmetics, ointments, creams, and topical medications. |
| 19.Quaternium-15 | Preservative in personal care products and cosmetics, shampoo, conditioners, moisturizers, shaving cream, talcum powder, and cooling fluid. |
| 20.Methylisothiazolinone/ Methylchloroisothiazolinone | Preservatives in personal care products, soap, liquid soap, shampoos, hair conditioners, hand soap, moisturizer, sunscreen, wet wipes, pet Shampoo, and cooling and lubricating fluids. |
| 21.Petrolatum (Negative control) | Used to differentiate negative reactions. |
| 22. Carba mix | Manufacturing of natural and synthetic rubber, gloves, boots, masks, ear- and headphones, swimwear, goggles, rubber bands, and erasers. Chemicals used as fungicides, and pesticides. May cross-react with thiuram mix. |
| 23.Imidazolidiny urea | Preservative in personal care products and cosmetics, moisturizers, hair conditioners, shampoos, deodorant, topical medication, and pet care products. |
| 24. Diazolidiny urea | Preservative in personal care products and cosmetics, moisturizers, liquid soap, hair care products, topical medicated ointment, and pet shampoos. |
| 25.Budesonide | Corticosteroid class B: topical cream/ ointment, inhaler. Including triamcinolone acetonide, fluocinonide, halcinonide, desonide. |
| 26.Tixocortol-21-pivalate | Corticosteroid class A: topical cream/ ointment, ear, nose, and eye drops, rectal suspension. Including hydrocortisone, prednisolone, and methylprednisolone. |
| 27. Decyl glucoside | Surfactants in skin and hair products, e.g. soap, and body washes. Used as a foaming agent for shampoos, emulsifier in cream and lotion, and wetting agent in perms. |
| 28. Methyl dibromo glutaronitrile | Cosmetic and personal care products, body creams, sunscreens, shower gels, shampoos, and medical products such as ultrasonic gel. Industrial products such as cutting oils, drilling oils, and coolants. |
| 29. Compositae mix I | Extracts of plants like sunflower, marigold, chrysanthemums, and German chamomile. Used in cosmetics, skin and hair care products, mouthwashes, topical medications, and herbal tea. |
| 30. Fragrance mix II | Contains Iyral, citral, farnesol, citronellol, hexyl cinnamic aldehyde, and coumarin. Used to add scent or flavor in perfume, cosmetics, soap, lotion, shampoo, hair conditioners, deodorant, toothpaste, laundry detergents, fabric softeners, air fresheners, scented candles, food, and drink. |
| 31. Hydroperoxides of Linalool | Perfumes, cosmetics, soaps, moisturizers, shampoos, hair conditioners, deodorants, household detergents, fabric softeners, and air fresheners. Used to add scent or flavor to food and beverages. |
