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Octylisothiazolinone—A New Sensitizer in Over-Ear Headphones

Berisha, Blerand LU ; Lejding, Tina LU orcid ; Bergendorff, Ola LU and Hauksson, Inese LU (2025) In Contact Dermatitis
Abstract

Background: Allergic contact dermatitis (ACD) caused by isothiazolinones is a growing concern, particularly in consumer products. Octylisothiazolinone (OIT) is a potent sensitiser and commonly used as a preservative in rubbers, plastics and coatings, including those found in headphones. Despite increasing regulations on isothiazolinones in cosmetics, their presence in wearable devices remains under-recognised. Aims: This investigation aims to identify OIT as a possible sensitiser in patients with presumed ACD due to over-ear headphones. Methods: Two patients with presumed ACD due to over-ear headphones were patch tested at the Department of Occupational and Environmental Dermatology, Skåne University Hospital, Malmö. Patch testing... (More)

Background: Allergic contact dermatitis (ACD) caused by isothiazolinones is a growing concern, particularly in consumer products. Octylisothiazolinone (OIT) is a potent sensitiser and commonly used as a preservative in rubbers, plastics and coatings, including those found in headphones. Despite increasing regulations on isothiazolinones in cosmetics, their presence in wearable devices remains under-recognised. Aims: This investigation aims to identify OIT as a possible sensitiser in patients with presumed ACD due to over-ear headphones. Methods: Two patients with presumed ACD due to over-ear headphones were patch tested at the Department of Occupational and Environmental Dermatology, Skåne University Hospital, Malmö. Patch testing included Swedish baseline series, isothiazolinone compounds, and materials from headphones. To identify potential allergens, chemical analysis of components from headphones was conducted using high-performance liquid chromatography (HPLC). Results: Patch testing demonstrated strong positive reactions to OIT in both cases, with additional reactions to acetone extracts of artificial leather and blue plastic foam. OIT remained positive at dilutions as low as 0.00003%. Case 1 also showed positive reactions to MI/MCI. Chemical analysis confirmed OIT in both artificial leather (2.2 mg/g) and plastic foam (0.3 mg/g). Conclusions: These findings contribute to the understanding of ACD by identifying OIT as a potential allergen in over-ear headphones. It calls for further research into the prevalence of OIT in consumer electronics and its role in sensitisation.

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Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
allergic contact dermatitis, octylisothiazolinone, over-ear headphones, patch test
in
Contact Dermatitis
publisher
Wiley-Blackwell
external identifiers
  • pmid:40944519
  • scopus:105015696528
ISSN
0105-1873
DOI
10.1111/cod.70028
language
English
LU publication?
yes
id
9ce0d486-cfd5-499b-8950-4c1d264c5175
date added to LUP
2025-11-12 14:29:39
date last changed
2025-11-13 03:00:03
@article{9ce0d486-cfd5-499b-8950-4c1d264c5175,
  abstract     = {{<p>Background: Allergic contact dermatitis (ACD) caused by isothiazolinones is a growing concern, particularly in consumer products. Octylisothiazolinone (OIT) is a potent sensitiser and commonly used as a preservative in rubbers, plastics and coatings, including those found in headphones. Despite increasing regulations on isothiazolinones in cosmetics, their presence in wearable devices remains under-recognised. Aims: This investigation aims to identify OIT as a possible sensitiser in patients with presumed ACD due to over-ear headphones. Methods: Two patients with presumed ACD due to over-ear headphones were patch tested at the Department of Occupational and Environmental Dermatology, Skåne University Hospital, Malmö. Patch testing included Swedish baseline series, isothiazolinone compounds, and materials from headphones. To identify potential allergens, chemical analysis of components from headphones was conducted using high-performance liquid chromatography (HPLC). Results: Patch testing demonstrated strong positive reactions to OIT in both cases, with additional reactions to acetone extracts of artificial leather and blue plastic foam. OIT remained positive at dilutions as low as 0.00003%. Case 1 also showed positive reactions to MI/MCI. Chemical analysis confirmed OIT in both artificial leather (2.2 mg/g) and plastic foam (0.3 mg/g). Conclusions: These findings contribute to the understanding of ACD by identifying OIT as a potential allergen in over-ear headphones. It calls for further research into the prevalence of OIT in consumer electronics and its role in sensitisation.</p>}},
  author       = {{Berisha, Blerand and Lejding, Tina and Bergendorff, Ola and Hauksson, Inese}},
  issn         = {{0105-1873}},
  keywords     = {{allergic contact dermatitis; octylisothiazolinone; over-ear headphones; patch test}},
  language     = {{eng}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Contact Dermatitis}},
  title        = {{Octylisothiazolinone—A New Sensitizer in Over-Ear Headphones}},
  url          = {{http://dx.doi.org/10.1111/cod.70028}},
  doi          = {{10.1111/cod.70028}},
  year         = {{2025}},
}