Contact Dermatitis, 1998, 38, 179 Copyright C Munksgaard 1998 Printed in Denmark . All rights reserved ISSN 0105-1873 Short Communication Allergic contact dermatitis from a neoprene elbow splint K. F T, S. M. W, R. J. G. C 1  M. H. B 1 The General Infirmary at Leeds, Great George Street, Leeds, UK 1 Hope Hospital, Salford, UK Key words: allergic contact dermatitis; neoprene; diphenylthiourea; orthopaedic splint; rubber. C Munksgaard, 1998. Case Report A 19-year-old woman was supplied with a neoprene splint to treat ‘‘tennis elbow’’. Talcum powder had been applied to the skin before using the support. A week later, she noticed a burning sensation of the skin and subsequently swelling and pruritus. She was admitted with a presumptive diagnosis of cellulitis and treated with penicillin V and flucloxacillin. When seen by a der- matologist, there was well-defined erythema localized to the area of the splint, associated with vesiculation and scale. There was no previous history of skin disease. She was treated with a short course of oral prednisolone and topical betamethasone valerate, with resolution of the suspected acute allergic contact dermatitis. Patch tests were performed to a standard series, a rub- ber chemical series and a sample of the splint. The posi- tive results are summarized in Table 1. The neoprene splint consisted of foam material fixed to knitted nylon fabric on both sides. It was later established that di- phenylthiourea was used within the adhesive. The splint did not contain cyclohexylthiophthalimide or tetram- ethylthiuram disulfide. Discussion Thiourea compounds are used in industry predom- inantly in the production of neoprene rubber where they have been shown to be the most effective vulcanization accelerators, and also to functions as antioxidants (1–7). Thioureas are also used as antioxidants in photocopy Table 1. Positive patch test results D2 D4 neoprene splint ππ ππ diphenylthiourea ππ ππ cyclohexylthiophthalimide ππ ππ tetramethylthiuram disulfide π ππ paper, and diphenylthiourea as a heat-stabilizer in PVC adhesive tape backing and adhesive plasters. Neoprene is the basis of many consumer items, including wet-suits, swimming goggles, protective gloves and orthopaedic de- vices, all of which have been implicated in cases of al- lergic contact dermatitis (1–5). Due to the lack of cross- reactivity between the substituted thioureas, it is import- ant to patch test with each compound separately (2). Orthopaedic conditions often require prolonged use of splints or supports that may have rubber components. A series of reports by Kanerva et al. (2) implicated vari- ous thiourea-containing products, including a knee- brace containing diethylthiourea. Romaguera et al. have described a reaction to an elastic elbow guard (3), and De Vallejo (4) has described diphenylthiourea allergy re- sulting from the use of a knee brace (4). References 1. Wilson H T H. Rubber dermatitis. An investigation of 106 cases of contact dermatitis caused by rubber. British Journal of Dermatology 1969: 81: 175–179. 2. Kanerva L, Estlander T, Jolanki R. Occupational allergic contact dermatitis caused by thiourea compounds. Contact Dermatitis 1994: 31: 242–248. 3. Romaguera C , Grimalt F, Vilaplana J, Castel C. Contact dermatitis to thioureas. Contact Dermatitis 1988: 18: 175– 176. 4. Villareal Balza De Vallejo O. Contact dermatitis from di- phenylthiourea in a knee brace. Contact Dermatitis 1997: 36: 166–167. 5. Dooms-Goossens A, Chrispeels M T, De Veylder H, Roel- andts R, Willems L, Degreef H. Contact and photocontact sensitivity problems associated with thiourea and its de- rivatives: a review of the literature and case-reports. British Journal of Dermatology 1987: 116: 573–579. 6. Estlander T, Jolanki R, Kanerva L. Dermatitis and urti- caria from rubber and plastic gloves. Contact Dermatitis 1986: 14: 20–25. 7. Van der Leun J C, De Kreek E J, Deenstra van Leeuwen H, Van Weelden H. Photosensitivity owing to thiourea. Archives of Dermatology 1977: 113: 1611.