CASE REPORT
A 69 years non‐atopic man presented with a 6 months history of pruriginous lesions started on his back with subsequent extension to his arms. At clinical examination, erythematosquamous plaques were present on his back, shoulder and arms (Figure 1A).
FIGURE 1.
(A) Well‐demarcated eczematous lesions on the upper back, shoulders and arms. (B) Patch tests positive for OIT (++) and leather car seat samples (++) at D4
The biopsy showed parakeratosis with intraepidermal oedema and spongiosis with lymphocyte exocytosis in epidermis consistent with eczematous dermatitis.
Topical corticosteroids allowed improvement but the lesions relapsed whenever they were stopped. The only change in his environment was his new car with leather seats.
Patch tests were performed with the European baseline series, a preservative, a textile series, a piece of his sofa's leather and a piece of his car seat's leather ‘as is’. Patch test materials were supplied by Chemotechnique Diagnostics. At the readings on Day (D) 2 and D 4, the patch tests showed positive results for octylisothiazolinone (OIT) 0.1% pet. (++) and the leather car seat samples (++) (Figure 1B). They were negative for methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) 0.01% aq., MI 0.2% aq. and benzisothiazolinone (BIT) 0.1% pet.
The patient has used two cream products for the treatment of his leather seats (Creams A and B). Both products lacked information about their composition. These two products as well as a small piece of car seat leather were sent for chemical analysis to the Official Food and Veterinary Control Authority of Geneva.
An amount 0.5 g of crushed leather was stirred in 5 ml of methanol (MeOH) and sonicated for 15 min. After 10 min of centrifugation (3500 RCF), the sample was analysed by high‐pressure liquid chromatography coupled to a diode array detector from Agilent Technologies. Separation was achieved using a Poroshell 120 EC‐C18 column (100 × 4.6 mm i.d.; 2.7 μm) from Agilent technologies maintained at 40°C with a gradient mobile phase consisting of 5 mM ammonium formate (pH 4.2) (Solvent A) and MeOH (Solvent B). The gradient started with 8% B for 1 min and then was linearly increased in serial plates: first to 25% B in 1 min, then to 30% B in 5 min, to 50% B in 4 min and to 70% B in 10.5 min. It was then further increased up to 100% B in 5.5 min and held for 2 min at the final composition. Gradient was then decreased to the starting composition in 0.1 min and equilibrated for 5 min before next injection.
Thiazolinone compounds were detected at 274 nm for MI and MCI, 280 nm for OIT and 318 nm for BIT. Two cream products (A and B) were also analysed in the same way. Results are reported in Table 1.
TABLE 1.
Results of chemical analysis
| MI (mg/kg) | MCI (mg/kg) | BIT (mg/kg) | OIT (mg/kg) | |
|---|---|---|---|---|
| Car seat leather | ND | ND | ND | 305 |
| Cream A | 19.3 | ND | 29.4 | ND |
| Cream B | ND | ND | ND | ND |
Abbreviations: BIT, benzisothiazolinone; MCI, methylchloroisothiazolinone; MI, methylisothiazolinone; ND, not detected; OIT, octylisothiazolinone.
OIT was identified and quantified at very high concentration (305 mg/kg) in the leather car seat and was not found in the protective creams suggesting that OIT was originally present in the leather.
DISCUSSION
OIT is a preservative agent with antifungal and antibacterial properties used in different products such as paints, household detergents, cutting and cooling fluids and the leather industry. In the last few years, multiples cases of non‐occupational allergic contact dermatitis to OIT in leather goods have been reported.1, 2 Since 2018, in our clinic, this case is the second reported case of leather contact dermatitis due to OIT. 3 In collaboration with the Official Food and Veterinary Control Authority of Geneva, 58 random leather goods from the Swiss market (belts, shoes for kids, sofa and etc.) were analysed and surprisingly, OIT was present in 55.1% of them (Table 2) with sometimes high concentrations up to 184 mg/kg (mean concentration: 44.7 mg/kg). Furthermore, the potential harmful effects of OIT on human health are still not well elucidated. Kim et al. 4 showed in their in vitro study that OIT induced blood brain barrier dysfunction.
TABLE 2.
Isothiazolinones concentration in leather goods
| Leather goods | MI (mg/kg) | MCI (mg/kg) | BIT (mg/kg) | OIT (mg/kg) |
|---|---|---|---|---|
| Adult Shoes | ND | ND | ND | ND |
| Children's shoes | ND | ND | ND | ND |
| Children's shoes | ND | ND | ND | ND |
| Children's shoes | ND | ND | ND | ND |
| Children's shoes | ND | ND | ND | ND |
| Adult flip flops | ND | ND | ND | 12.7 |
| Gloves | ND | ND | ND | ND |
| Gloves | ND | ND | ND | ND |
| Adult clogs | ND | ND | ND | 14.1 |
| Children's slippers | ND | ND | ND | ND |
| Children's slippers | ND | 3.9 | ND | ND |
| Children's slippers | ND | ND | ND | ND |
| Children's shoes | ND | ND | 11.1 | 19 |
| Baby slippers | ND | ND | ND | ND |
| Baby slippers | ND | ND | 29.9 | ND |
| Baby slippers | ND | ND | ND | 18.7 |
| Gloves | ND | ND | ND | ND |
| Gloves | ND | ND | ND | ND |
| Shoes | ND | ND | ND | 15.5 |
| Shoes | ND | ND | ND | ND |
| Soles | 10.3 | ND | 14.8 | 12.4 |
| Children's slippers | ND | 9 | 29.3 | 8.9 |
| Adult clogs | ND | ND | ND | ND |
| Adult slippers | 8.6 | ND | 18.5 | 95.6 |
| Gloves | ND | ND | ND | 11.5 |
| Gloves | ND | ND | ND | ND |
| Gloves | ND | ND | ND | 9.9 |
| Gloves | ND | 3 | ND | 23.9 |
| Soles | ND | ND | 31.5 | ND |
| Hat | ND | 3.1 | 9.2 | 157.8 |
| Heel pads | ND | ND | ND | ND |
| Soles | ND | ND | ND | ND |
| Children's shoes | ND | ND | 9 | 8.9 |
| Children's shoes | ND | ND | 10.1 | 18.7 |
| Children's shoes | ND | ND | ND | ND |
| Children's shoes | ND | ND | 15.8 | 158 |
| Adult flip flops | ND | ND | ND | ND |
| Adult sandals | ND | ND | ND | ND |
| Children's shoes | ND | ND | 10.7 | 54 |
| Children's shoes | ND | 8.4 | ND | 11.6 |
| Children's shoes | ND | ND | ND | 27.9 |
| Children's shoes | ND | ND | ND | 14.7 |
| Children's shoes | ND | ND | ND | ND |
| Children's shoes | ND | ND | ND | 33.7 |
| Children's shoes | ND | ND | ND | ND |
| Children's shoes | 19.2 | ND | ND | 8.1 |
| Children's shoes | ND | ND | 8.9 | 8.3 |
| Children's shoes | 20.5 | ND | ND | 7.4 |
| Children's shoes | ND | ND | 20.1 | 36.6 |
| Children's shoes | ND | ND | 9.2 | 17.6 |
| Children's shoes | ND | ND | ND | ND |
| Children's shoes | 8.5 | ND | ND | ND |
| Sofa | ND | ND | 11.3 | 184 |
| Sofa | ND | ND | 8 | 131 |
| Sofa | ND | ND | 8.8 | 88.9 |
| Sofa | ND | ND | 23.5 | 97.5 |
| Sofa | 9.9 | ND | 14.3 | 83.6 |
| Sofa | ND | ND | 8 | 40.7 |
Abbreviations: BIT, benzisothiazolinone; MCI, methylchloroisothiazolinone; MI, methylisothiazolinone; ND, not detected; OIT, octylisothiazolinone.
Currently, there is no European legislation regarding the maximum authorized concentration of OIT in leather goods. As their usage increases, careful monitoring of contact allergy to this preservative seems indicated.
AUTHOR CONTRIBUTIONS
Yassaman Alipour Tehrany: Conceptualization; writing – original draft; writing – review and editing. Raphael André: Writing – review and editing. Aurélie Bugey: Conceptualization; writing – review and editing; methodology; investigation. Doriane Santimaria: Investigation. Patrick Edder: Supervision. Pierre Piletta: Conceptualization; writing – review and editing; supervision.
CONFLICT OF INTEREST
The authors declare no conflicts of interest.
ACKNOWLEDGEMENT
Open access funding provided by Universite de Geneve.
Alipour Tehrany Y, André R, Bugey A, Santimaria D, Edder P, Piletta P. Allergic contact dermatitis caused by octylisothiazolinone in a leather car seat: Case report and emergence of octylisothiazolinones in leather goods in Switzerland. Contact Dermatitis. 2022;87(5):455‐457. doi: 10.1111/cod.14188
REFERENCES
- 1. Aerts O, Meert H, Romaen E, et al. Octylisothiazolinone, an additional cause of allergic contact dermatitis caused by leather: case series and potential implications for the study of cross‐reactivity with methylisothiazolinone. Contact Dermatitis. 2016;75:276‐284. [DOI] [PubMed] [Google Scholar]
- 2. Hunt WTN, Dunnill MG, Sansom JE. Sofa dermatitis again? A case report of allergic contact dermatitis to octylisothiazolinone from a leather reclining chair. Contact Dermatitis. 2020;82:161‐162. [DOI] [PubMed] [Google Scholar]
- 3. Alipour Tehrany Y, Quenan S, Bugey A, Piletta P. Allergic contact dermatitis caused by octylisothiazolinone in a leather sofa. Contact Dermatitis. 2018;79:188‐189. [DOI] [PubMed] [Google Scholar]
- 4. Kim D, Kim EH, Choi S, et al. A commonly used biocide 2‐N‐octyl‐4‐isothiazolin‐3‐oneInduces blood‐brain barrier dysfunction via cellular thiol modification and mitochondrial damage. Int J Mol Sci. 2021;22:2563. [DOI] [PMC free article] [PubMed] [Google Scholar]