We present a case of contact dermatitis due to cellular phone use.
A 35-year-old Japanese woman presented with a 2-week history of pruritic erythema and papules on the preauricular portion of her left cheek when she was first examined at our hospital on September 11, 2000 (Figure 1, A) and was later diagnosed as having allergic contact dermatitis likely caused by hexavalent chromium plating on a cellular phone. She had started using a new cellular phone (Figure 1, B) on August 15, 2000, and used it 5 to 10 times for a total of 2 to 2.5 hours per day, usually on her left side. The patient does not usually wear makeup. A closed patch test using the commercially available Torii Patch Test Standard Series (Torii Co, Tokyo, Japan) in petrolatum was performed for various kinds of metals (2% aluminium chloride, 0.2% tetrachloroauric acid, 1% tin chloride [II], 2% iron chloride [II], 0.5% hexachloroplatinic acid, 1% palladium chloride, 1% indium trichloride, 1% iridium tetrachloride, 2% zinc chloride, 2% manganese chloride, 2% silver bromide, 2% cobalt chloride, 0.05% mercury chloride [II], 0.5% potassium dichromate, 2% chromium sulfate, 1% copper sulfate, and 5% nickel sulfate). In addition, a patch test using the Japanese Society for Contact Dermatitis standard allergen series (27 items) was performed. When the reactions were evaluated 48 and 72 hours after application, the test results were strongly positive (++) only for 0.5% potassium dichromate according to the International Contact Dermatitis Research Group criteria1 for patch testing. The patch test results were also positive for 0.1% and 0.05% potassium dichromate. A photopatch test showed the same results. Laboratory data were all within the normal range. A diagnosis of contact dermatitis caused by hexavalent chromium was made, and the skin eruptions disappeared approximately 10 days after she stopped using the cellular phone, which suggests that the cellular phone was the cause of the contact dermatitis in this case because the pink part in the figure (Figure 1, B) is plated with chromium.