Allergic contact dermatitis caused by a blood pressure cuff

Allergic contact dermatitis caused by a blood pressure cuff To the Editor: N-isopropyl-N-phenyl-p-phenylenedi-amine (IPPD) is used primarily in the manufacture of black rubber products and its cross-reactivity with p-phenylenediamine (PPD), a common hair dye, is possible. A 78-year-old nonatopic woman with a history of hypertension and coronary artery disease underwent a dipyridamole stress echocardiography. During this procedure, her blood pressure was monitored for 45 minutes. One day later, a pruritic, sharply demarcated, erythematous vesicular eruption developed at the site of contact with the blood pressure cuff. Slight improvement was obtained with topical corticosteroids and the dermatitis completely cleared after 7 days of treatment with oral corticosteroids. A clinical diagnosis of contact dermatitis due to the blood pressure cuff was made. One month later, the woman was patch tested with the standard Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) series. At day 2 and day 4, a positive reaction to IPPD (0.1% in petrolatum) was recorded. PPD (1% in petrola-tum), included in the standard series, did not show a positive reaction. Strong response was elicited when a fragment of the blood pressure cuff was patch tested as is. A skin prick test to latex protein was negative. In addition, the patient gave a positive history of hand eczema to rubber gloves. The inner part of the sphygmomanometer was composed of black rubber and lined by a nylon cuff. According to the manufacturer, there is no information available concerning the composition of the rubber. Chemical analysis was conducted to verify the presence of IPPD in the nylon cuff. In previous studies, the determination of IPPD was carried out by gas chromatographyemass spectrometry and high-performance liquid chromatography (HPLC). In this study, after incubation with ichloromethane (CH2Cl2) for 24 hours, a piece of tissue extracted from the nylon section of the sphygmomanometer was submitted to HPLC interfaced with an API3000 mass spectrometer that was triple quadrupole equipped with a turbo ion spray. Spectroscopy was comparatively performed on the standard IPPD allergen. The quasimolecular ion m/z 227 [M 1 H] and the fragment m/z 184 confirmed the presence of IPPD in the tissue which had a sample content of 38.5 ppm. To our knowledge, this is the first report describing allergic contact dermatitis due to IPPD in a blood pressure cuff. Orthopedic textile knee bandage and orthopedic hip brace have been reported to cause sensitivity to IPPD. Contact dermatitis after ambulatory blood pressure monitoring was reported in 2012; however, those authors did not provide information regarding the responsible allergens. The lack of interface between the nylon and rubber components and the repeated use of the sphygmomanometer could have caused the passage of the allergen by way of direct contact with the skin. The duration of sweating and occlusion (45 minutes) may also have favored the development of dermatitis. We emphasize the importance of chemical analysis and the possible risk of allergic contact dermatitis even during a medical test that is generally considered to be a safe procedure.