Colophony-induced contact dermatitis due to ECG electrodes in an infant Contact Dermatitis 2007: 56: 177–178 Elsbeth Oestmann, Sandra Philipp, Torsten Zuberbier and Margitta Worm Allergie-Centrum-Charite ´, Klinik fu ¨r Dermatologie, Venerologie und Allergologie, Charite ´ Universita ¨tsmedizin, Berlin, Germany Key words: allergic contact dermatitis; colo- phony; ECG; electrode; infant; patch testing. Contact dermatitis from electrocar- diogram electrodes has been repeat- edly reported lately (1–3). Allergic and irritant origins are being dis- cussed. Case Story A 5-month-old female infant under- went continuous ECG monitoring at home for the prevention of sudden infant death. Self-adhesive prewired paediatric monitoring electrodes (Kendall Kittycat Foam 4203; Tyco Healthcare, Chicopee, MA, USA) were fixed to the chest wall. One elec- trode was used for up to 4 days. 4 weeks after initial use, confluent erythematous papules developed at the electrode sites. Similar symptoms developed when using another elec- trode type (Kendall Arbo Premie H87P; Tyco Healthcare). The contact area of both types of Ag/AgCl electrodes is coated with a conductive adhesive hydrogel- contains synthetic polymers and acrylate adhesives. Patch testing with possible contact allergens was per- formed. According to the Guidelines of the German Contact Dermatitis Research Group (DKG), colophony 20% pet., p-tert-butylphenol-formal- dehyde resin 1% pet., propylene glycol 20% aqueous, hydroxyethyl methacrylate 1% pet., methyl meth- acrylate 2% pet. and the adhesive electrodes were tested. 72-hr scoring showed a twofold positive reaction to colophony and positive reactions to both sides of the first electrode and the adhesive side of the second elec- trode. All other substances tested negative. There was no previous history of atopy in the infant. The mother was known to suffer from allergic rhinitis. Discussion The frequency of allergic contact dermatitis in children is often under- estimated (4). We could detect posi- tive patch test reactions to adhesive ECG electrodes due to colophony in an infant. According to the manufac- turer, colophony is not a regular part of the electrode hydrogel. However, colophony is used when soldering the electrode cables and metal contact plates. Long occlusive skin contact may well dissolve the colophony residues within the contact gel. As a consequence, unsoldered monitor- ing electrodes (Kendall Arbo Premie H207PGT; Tyco Healthcare) were used for further monitoring of the infant. The contact sites remained unremarkable from then on. To our knowledge, this is the first report of an allergic contact dermatitis due to colophony in an ECG electrode. Propylene glycol (1) is a common trigger of allergic contact derma- titis in adhesive ECG electrodes. Pro- pylene glycol is often part of the hydrogel. Acrylates (2) and p-tert- butylphenol-formaldehyde resin (3) could also be identified as hidden allergens in ECG electrodes. In our case, no type IV sensitization to these substances was detected. References 1. Connolly M, Buckley D A. Contact dermatitis from propylene glycol in ECG electrodes, complicated by medi- cament allergy. Contact Dermatitis 2004: 50: 42. 2. Jelen G. Acrylate, a hidden allergen of electrocardiogram electrodes. Contact Dermatitis 2001: 45: 315–316. 3. Avenel-Audran M, Goossens A, Zimerson E, Bruze M. Contact derma- titis from electrocardiograph-monitoring CONTACT POINTS 177