If Left to Your Own Devices, Consider Colophony

A 37-year-old female with Type 1 diabetes reported a 1-year history of an erythematous, papular and blistering eruption on her abdomen and lateral thighs which correlated with application sites of her Omnipod CSII insulin pump (Insulet Corporation, Acton, Massachusetts) and Dexcom G6 glucose sensor (Dexcom Inc., San Diego, California). Her regimen for device application included: isopropyl alcohol wipe, 3M Cavilon No Sting Barrier wipe (3M Inc., Saint Paul, Minnesota), SKIN TAC adhesive wipe (Torbot Group Inc., Cranston, Rhode Island), IV 3000 transparent adhesive film dressing (Smith & Nephew Inc., Mississauga, Ontario, Canada), then the diabetes-related-device (DRD). On examination, there were multiple well-demarcated dermatitic plaques on the abdomen and thighs (Figure 1). The patient was patch tested to the North American Contact Dermatitis Group Screening and Supplement series (Chemotechnique Diagnostics, Vellinge, Sweden), the methacrylate/acrylate adhesive series (Chemotechnique), methylene-bis monoacrylate 1.0% in petrolatum (custom preparation) and SKIN-TAC adhesive wipe (semi-occlusive). After 96 h, reactions were noted to colophonium 20.0% in petrolatum (1+) and SKIN-TAC (1+). Previous literature indicated colophony was an ingredient in the SKIN-TAC, Omnipod CSII and Dexcom G6 [1-5]. Our patient strongly preferred the tubeless Omnipod CSII and found the Dexcom G6 user-friendly. Therefore, we recommended she discontinue the adhesive wipes but otherwise continue with her DRDs over unaffected skin. Within 1 month, her dermatitis resolved and new application sites were clear. Allergic contact dermatitis to insulin pumps, glucose sensors and their adhesive components is reported frequently [1-5]. Usually, the allergens are a component within the DRD. Isobornyl acrylate is the most commonly recognised allergen, but multiple reports identified colophony as relevant [1-5]. Because our patient subsequently tolerated her DRDs after selective discontinuation of SKIN-TAC, further investigation was conducted. The manufacturer of SKIN-TAC discloses colophony in their product, with a concentration by weight of < 18% [6]. Allergic contact sensitization may occur because SKIN-TAC is applied wet, air dried, then occluded [7]. The Omnipod CSII was previously reported to contain colophony, however, the manufacturer disclosed to us that their internal analysis did not show colophony or related substances [2, 8]. The components had not changed, and are consistent worldwide [8]. The Dexcom G6 adhesive patches analysed via gas chromatography–mass spectrometry suggested the presence of a colophony-related substance, but further investigation was recommended [5]. In summary, SKIN-TAC may have been the only relevant exposure for the patient. This case illustrates the value of eliciting a comprehensive inventory of all contactants, investigating products as needed, and formulating a logical management plan. After selective discontinuation of the adhesive wipes, the skin remained free from dermatitis. The patient considered this a ‘game-changer’. E. Dimitra Bednar: writing – original draft, writing – review and editing. Joel G. DeKoven: conceptualization, writing – review and editing, supervision, investigation. Informed consent was received from all participants. The authors declare no conflicts of interest.