A new Mayo Clinic study reveals the most common causes of allergic contact dermatitis, a skin inflammation resulting in swollen, reddened and itchy skin due to direct contact with an allergen.
Topping the list were:
- Nickel (nickel sulfate hexahydrate) - metal frequently encountered in jewelry and clasps or buttons on clothing
- Gold (gold sodium thiosulfate) - precious metal often found in jewelry
- Balsam of Peru (myroxylon pereirae) - a fragrance used in perfumes and skin lotions, derived from tree resin
- Thimerosal - a mercury compound used in local antiseptics and in vaccines
- Neomycin sulfate - a topical antibiotic common in first aid creams and ointments, also found occasionally in cosmetics, deodorant, soap and pet food
- Fragrance mix - a group of the eight most common fragrance allergens found in foods, cosmetic products, insecticides, antiseptics, soaps, perfumes and dental products
- Formaldehyde - a preservative with multiple uses, e.g., in paper products, paints, medications, household cleaners, cosmetic products and fabric finishes
- Cobalt chloride - metal found in medical products; hair dye; antiperspirant; objects plated in metal such as snaps, buttons or tools; and in cobalt blue pigment
- Bacitracin - a topical antibiotic
- Quaternium 15 - preservative found in cosmetic products such as self-tanners, shampoo, nail polish and sunscreen or in industrial products such as polishes, paints and waxes
This study, to be presented Monday at the American Academy of Dermatology annual meeting in San Francisco, confirmed that patch testing with a standard contact dermatitis series of substances is useful for identifying common contact allergens. Patch testing is conducted by placing potential allergens covered with patches on patients' backs for two days and then observing which substances cause skin inflammation. The study confirmed previous findings by the North American Contact Dermatitis Group.
The researchers examined contact dermatitis testing results from 3,854 patients over a five-year period between Jan. 1, 2001 and Dec. 31, 2005. The patients were tested with an average of 69 allergens. Of these patients, 2,663 (69 percent) had at least one positive reaction, and 1,933 (50 percent) had two or more positive reactions.