Dear members,

To limit the number of emails received via forum posts, the monthly Bitesize Updates will be posted under the News section from now on. This will also enable easy reference to previous Bitesize Updates as well. We have included here 4 recent publications which may be of interest:

Virtual Reality Headset as a Cause of Allergic Contact Dermatitis in a Child

Eid D, Akhtar S, Stone N (October 19, 2025) Virtual Reality Headset as a Cause of Allergic Contact Dermatitis in a Child. Cureus 17(10): e94906. doi:10.7759/cureus.94906

Our colleagues in Newport report the first paediatric case of virtual reality (VR) headset-associated ACD. A 13-year-old boy presented with persistent periorbital and upper cheek eczematous change, areas in direct contact with his VR headset (Oculus Quest 2, Meta Platforms). Extensive patch testing elicited a reaction to: MI, MCI/MI, benzisothiazolinone (BIT), Bronopol, methyldibromoglutaronitrile, propolis, Carba Mix, and to foam from the headset itself. As chemical analysis was not performed, presence and relevance of all allergens could not be confirmed. Use of silicone cover in place of the foam resulted in complete resolution. This case highlights that wearable-devices can be a cause of ACD and the importance of inclusion of device material in diagnostic patch testing.

Positive Patch Test Reaction to Sodium Metabisulfite: Prevalence, Relevance and Clinical Implications

Casciola G, Stingeni L, Bianchi L, Agostinelli D, Tramontana M, Hansel K. Positive Patch Test Reaction to Sodium Metabisulfite: Prevalence, Relevance and Clinical Implications. Contact Dermatitis. 2025 Nov 5. doi: 10.1111/cod.70050. PMID: 41194600

Sodium metabisulfite (SMB) is widely found as a preservative in cosmetics, food/beverage and drugs such as epinephrine (adrenaline)-containing local anaesthetics. Attribution of relevance of SMB patch test reactions can be difficult due to ubiquitous presence in products. This retrospective study from Perugia, Italy assessed 16 SMB patch test positive patients (prevalence 2.9% of 550 tested patients) between January 2024 and April 2025. Fourteen of these had strong or extreme reactions on day 4. No clinical relevance was identified in any of the 16 patients. Delayed-reading intradermal testing (IDT) with SMB 1% in saline was performed, followed by challenge with dermal injections of 0.9mL (0.1 mL, 0.3 mL, and 0.5 mL at 30 minute intervals) of mepivacaine and epinephrine containing 0.025% SMB if negative on IDT. All tested negative on intradermal and challenge test. Findings from this study suggests high prevalence without clear relevance to SMB and positive patch test may not contraindicate systemic exposure, such as though local anaesthetic administration.

 Caprylyl Glycol, a Trending and Highly Relevant Sensitiser in Cosmetics That Needs to be Patch Tested Separately

Kanokrungsee S, Dendooven E, Aerts O. Caprylyl Glycol, a Trending and Highly Relevant Sensitiser in Cosmetics That Needs to be Patch Tested Separately. Contact Dermatitis. 2025 Nov;93(5):418-421. doi: 10.1111/cod.70019. Epub 2025 Aug 26. PMID: 40855841.

Alternative preservatives, termed ‘para-preservatives’ are increasingly used in cosmetics and personal care products in place of traditional preservatives. One such preservative, caprylyl glycol (CG) (1,2-octanediol) has rarely been reported to cause ACD. Retrospective analysis of a 4-year period (January 2021 – December 2024) from a single centre in Antwerp identified 9 positive CG patients, predominantly affecting the face (n=5). Initial testing was performed with 5% pet obtained from a cosmetic company and subsequently with 1% pet due to limited availability. Prevalence on testing to both concentrations was 0.77% and 0.12%, at the 5% and 1% concentrations respectively. CG was present in patients’ products in 8 cases, with all improving with avoidance of identified allergens. Three of the products were labelled as being ‘hypoallergenic’. Concominant allergy to propylene glycol (PG) was not common despite similar structure as only 2 patients tested positive to PG as well. This study shows CG is an emerging allergen, particularly in cosmetics and ‘hypoallergenic’ items, and testing with 5% pet should be considered.

Nickel Contact Allergy in an Australian Patch Testing Centre Over 2014-2023

Brasher TR, Palmer A, Nixon R. Nickel Contact Allergy in an Australian Patch Testing Centre Over 2014-2023. Australas J Dermatol. 2025 Oct 25. doi: 10.1111/ajd.14611. Epub ahead of print. PMID: 41137537.N

Nickel is a common cause of ACD and unlike the European Union where there is regulation regarding presence of nickel in items in prolonged contact with skin, no such legislation exists in Australia. The Skin Health Institute in Melbourne conducted a retrospective audit spanning 10 years, showing a prevalence of 16.0% (573 of 3582 patients), whereby 4.7% were deemed relevant and 11.8% due to occupation causes. There was an overall trend of reduced relevance of patch test positive patients over the period despite stable prevalence. Occupation-related nickel ACD was comparable to 11.7% prevalence in 1993-2010 reported by the centre previously. Despite the decrease in assessed relevance of nickel patch test positive reactions, no clear cause of this was identified although the authors considered the possibility of reduction in amount of nickel in consumer products such as in coins.