Pulpitis of the fingers, it is not always acrylates!

An 8-year-old patient with a 4-year history of type 1 diabetes mellitus and a past history of atopic dermatitis during infancy presented with pruritic, scaly and fissured lesions on the first three fingers of both hands, primarily on the fingertips (the patient is right-handed) (Figure 1). He was being treated with a subcutaneous Minimed 640G pump from the onset of diabetes and had been using the FSL2 sensor for glycemic control for a few months. However, he developed quickly itchy, erythematous and vesicular lesions at the application sites, followed by secondary desquamation. He had previously experienced similar cutaneous reactions with the Entlite glucose sensor used from the onset of diabetes, a few weeks after its first use and since the same time, he has complained of pruritus around the insulin pump, which persists to this day. The onset of pulpitis followed the skin reactions caused by the two sensors. His mother recalled that he had been handling ‘Superhero’ stickers a few times just before the pulpitis appeared. Patch tests were performed on the upper back using IQ Ultra chambers (Chemotechnique Diagnostics, Vellinge, Sweden) occluded for 2 days with Opertape (Iberhospitex, Innovative Health Technologies, Barcelona, Spain). The tests included the European baseline series, additional series from the REVIDAL group (Réseau de Vigilance en Dermato-Allergologie du Groupe d'Etude et de Recherche en Dermato-Allergologie), an acrylate series including isobornyl acrylate and ethyl hexyl acrylate, and a modified rosin (provided by an adhesive bandage manufacturer). A sticker was also applied to his arm as an open test with the glue side facing the skin. All tests were read on days (D)2 and D3 according to ESCD recommendations.1 Positive reactions were observed with colophonium (20% pet) (+ on D2 and D3), modified colophonium, a methyl ester of rosin (20% pet) (+ on D2 and D3) (Figure 2A). The acrylate series was negative, including results on D7. The superhero sticker showed a positive reaction on D3 (+) (Figure 2B). For chemical analysis of the stickers, acetone extracts of a few stickers were analysed using gas chromatography-mass spectrometry.2 Substances related to colophonium-based adhesives, for example, methyldehydroabietate and dehydroabietic acid could be identified in the extract, as well as ethyl hexyl acrylate. The concentration of colophonium derivatives could not be determined. No recurrence of pulpitis was observed after the patient avoided contact with the stickers. The patient was also advised to avoid contact with products that may contain colophonium or its derivatives, especially some hydrocolloid dressings used between the medical devices and the skin to prevent skin reactions. At distance, we contacted by phone his mother who told us that finally he was still using the FSL 2 sensor because of a better tolerance with time but unfortunately, the Minimed 640 G insulin pump had to be removed because of the persistence of a severe eczema around and he had to take subcutaneous insulin injections. This case is the first report of pulpitis in a child linked to a contact allergy to modified rosin present in stickers. Acrylates are well-known as the primary cause of allergic contact pulpitis, particularly among dental technicians and users or technicians of artificial nails or semi-permanent nail varnishes.3, 4 In this case, identifying the responsible allergen was particularly challenging because the blood glucose sensors to which the patient reacted are known to contain both acrylates and colophonium derivatives.5 Our patient most likely was sensitised to colophonium by the medical device Entlite glucose sensor. In a recent study, eight patients who used Enlite glucose sensor, Enlite tape, and/or Paradigm pump, reacted to colophonium or the related substances abitol and/or abietic acid.6 It is noteworthy that colophonium in the European standard series tested positive, which is not always the case in allergic contact dermatitis related to modified colophonium.7 Contact allergy to components of medical devices, such as blood glucose sensors, is well-documented.7-9 Unfortunately, allergy to colophonium can also lead to allergic contact dermatitis from other everyday items, including those used by children during leisure activities, as was the case here with stickers. Nadia Raison-Peyron: Supervision; writing – review and editing; writing – original draft; investigation; methodology; validation; visualization; conceptualization. Marwa El Gana: Writing – review and editing; methodology; investigation; conceptualization. Cecilia Svedman: Writing – review and editing; supervision; validation; investigation; methodology. Jakob Dahlin: Investigation; methodology; writing – review and editing; validation; supervision. The authors declare no conflicts of interest.