Contact Dermatitis • Contact Points TWO CASES WITH OCCUPATIONALLY RELEVANT EXPOSURE • LENSEN ET AL. Contact allergy to di-isodecyl phthalate

Key words: allergic contact dermatitis; occupational; plastics. Di-isodecyl phthalate (DIDP) is a plasticizer used in the production of plastic and plastic coating to increase flexibility. It is a mixture of compounds derived from the esterification of phthalic acid and isomeric decyl alcohols. In a facility producing durable vinyl-coated cover material on a dyed backing paper base, we found 2 workers with a positive patch test reaction to DIDP. DIDP was used as a carrier for 10,10’-oxybisphenoxarsine (CAS 58-36-6), a biocide used in products to protect the vinyl-coated materials from decay by mould, mildew, and bacteria. Case 1 A 53-year-old male reported an itching dermatitis with papules, scaling and erythema on both forearms, marking the border of the gloves used during his work as an operator. No signs of dermatitis were seen elsewhere on his body. There were no signs of atopy in his medical history. The complaints started without any change in exposure of the skin. Treatment by the general practitioner with a topical steroid helped in periods of exacerbation of the skin complaints. During holidays, the skin problems diminished. Over time, the period needed for relapse after work resumption shortened from weeks to days. Case 2 A 61-year-old male with atopic dermatitis reported suffering skin complaints of red, itchy bumps on both arms, his trunk and his legs for over 6 years. Erythematous papules on the forearms, legs and trunk were seen on dermatological inspection