Dear members,

This month’s edition selection covers the diverse causes and clinical presentation of chronic hand eczema, skin penetration and lipid effects of fragrance terpene hydroperoxides, the prevalence and clinical relevance of formaldehyde contact allergy, and an occupational case of allergic contact dermatitis caused by disperse dyes in paint.

Moderate to Severe Chronic Hand Eczema in Clinical Practice: Etiological Subtypes, Clinical Signs and Symptoms, and Comorbidities—Results From the RWEAL Study.

C. Fargnoli, S. Molin, A. Bewley et al. Journal of Dermatological Treatment. 2026; 37(1): 2603121.

This multinational chart review included 1,939 adults with moderate-to-severe chronic hand eczema (CHE) across six countries. Irritant contact dermatitis was the most common aetiological subtype (40.1%), followed by atopic dermatitis (33.1%) and allergic contact dermatitis (27.5%), with the latter more common in patients with severe disease. More than one subtype was identified in 14.2% of patients. The palms, fingertips and backs of the hands were most frequently affected, and erythema, pruritus and scaling were the most common clinical features. A history of atopic dermatitis was reported in 43.8%, supporting CHE as a heterogeneous condition with multiple possible aetiologies rather than simply atopic dermatitis affecting the hands

Absorption and Effects of Patch Test Preparations of Hydroperoxides of Limonene and Hydroperoxides of Linalool in Human Ex Vivo Skin.

A. Clancy, L. Hagvall, P. Malmberg and N. M. O’Boyle, Contact Dermatitis. 2026; 95: 159–168,

This ex vivo study used Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) imaging to examine the skin penetration of patch test preparations of hydroperoxides of limonene 0.3% and linalool 1.0%, and their effects on skin lipids. After 24 hours, both hydroperoxides were largely confined to the stratum corneum, with lower levels detected in the viable epidermis. Hydroperoxides of linalool altered levels of several stratum-corneum lipids, including cholesterol, monoacylglycerols, diacylglycerols and phosphatidylcholines. Similar trends were observed with hydroperoxides of limonene, although changes in individual lipid species did not reach statistical significance. Overall, the findings indicate that fragrance terpene hydroperoxides are absorbed into human skin and can alter its lipid composition, particularly within the stratum corneum, although the clinical significance remains uncertain.

The Prevalence of Contact Allergy to Formaldehyde and Formaldehyde Releasers: A Systematic Review and Meta-Analysis.

K Karimian, D. Isufi, M. B. Jensen et al. Contact Dermatitis. 2026; 95: 125–147,

This systematic review and meta-analysis of 158 studies involving over 1.3 million dermatitis patients found a pooled prevalence of formaldehyde contact allergy of 2.88%, with 41.6% of positive reactions considered clinically relevant. Among formaldehyde releasers, sensitisation was highest to 2-bromo-2-nitropropane-1,3-diol (2.76%) and quaternium-15 (1.89%), the latter having the highest clinical relevance (55.7%). Prevalence varied geographically, being highest in North America (6.8%) compared with Europe (2.3%) and Southeast Asia (1.8%), but did not differ significantly by age or atopic dermatitis status. Overall, formaldehyde and its releasers remain relevant contact allergens, with substantial regional variation potentially reflecting differences in regulation and exposure.

Occupational Allergic Contact Dermatitis in a Wall Painter: Identification of Disperse Yellow as the Causative Agent.

Rozas LM, Andreu-Barasoain MI, Valdés AM, Estebaranz JLL. Contact Dermatitis. 2026 Aug;95(2):223-226.

This case report describes occupational allergic contact dermatitis in a 47-year-old wall painter exposed to industrial paints containing Disperse Yellow dyes. Patch testing showed strong reactions to PPD and a textile dye mix, with further testing identifying positive reactions to Disperse Yellow 3 and Disperse Orange 1 and 3. Disperse Yellow dyes were identified in work paints; symptoms recurred after unprotected paint exposure. Episodes of unilateral facial dermatitis associated with his partner’s use of PPD-containing hair dye, which resolved when the partner stopped using it, consistent with connubial allergic contact dermatitis. The case highlights disperse dyes as potential occupational allergens in paint and the importance of considering indirect household exposure.

EPIDERM is the national surveillance scheme for occupational skin disease in the UK. It is part of The Health and Occupational Research (THOR) scheme run from the University of Manchester.

EPIDERM is the only national surveillance programme for occupational skin disease in the UK. Trends and emerging risks identified through EPIDERM inform patient care, policy and research. This leads to prevention of disease for future workers and supports earlier disease detection. 

Contribute to EPIDERM by reporting cases of occupational skin disease.

⭐ Benefits of Taking Part

As well as contributing cases to crucial national surveillance and directly influencing clinical care, research and policy for patients with occupational skin disease, EPIDERM reporters can:

• 📈 Access data from EPIDERM for audit, governance, QI or research;
• 🤝 Develop case reports and research projects with the THOR team for publication;
• 🔍 Access free, regular CPD across a breadth of occupational and environmental health issues through the THOR seminar series, blogs and Lane Lecture. 

🚨 Reporting

• Reporting is via an easy online form and takes 3-5 minutes per case submitted. Look here for testimonials. 
• Reporters can choose be a sample or core reporter. Sample reporters submit all cases seen in one randomly allocated month of the year. Core reporters submit all cases seen each month. 
• You can report as an individual or group.
• Responsibility for reporting can be shared between clinicians in groups. 
• If you have any questions about reporting, please get in touch. 

✍️ Join in under 2 minutes

• Clinicians who are consultants or who are working under a named consultant (for example resident doctors, clinical nurse specialists or other AHPs) can report to EPIDERM.  

Dear members,

This month, we feature three summaries of recent publications covering MCI/MI exposure in cosmetics, patch testing for dental material allergy, and the prevalence of alkyl glucosides in cosmetic products:

Methylisothiazolinone 10 Years After Regulation: A Case Story of Liquid Soaps and Shampoos

Pedersen MK, Schwensen JFB, Alfonso JH et al. Contact Dermatitis. 2026 Jun 16. doi: 10.1111/cod.70202. PMID: 42300206.

Pedersen et al. investigated the use of MCI/MI in marketed cosmetics10 years after EU regulatory changes. From a Danish database, 257 (2.5%) products containing MCI/MI or MI were identified, most commonly shampoos and conditioners. Chemical analysis (LC-MS/MS) was performed on 30 rinse-off products. While most complied with current legislation, two liquid hand soaps exceeded the permitted 15 ppm concentration, and four products did not meet the required MCI:MI ratio (3:1). However, only products declaring MCI/MI or MI were included in the chemical analyses. Despite a marked reduction in overall use compared with the pre-regulation era, MCI/MI remains a clinically relevant allergen. The findings raise questions about whether the current 15 ppm limit is sufficiently protective, particularly for frequently used rinse-off products such as hand soaps, and support continued compliance monitoring, surveillance, and more proactive approaches to preservative risk assessment and management.

Patch Test Reactions to Dental Materials: A Retrospective Single-Centre Study

Bizjak-Suran M, Marčun M, Košnik M, Dinevski D. Contact Dermatitis. 2026 Jun 16. doi: 10.1111/cod.70205. PMID: 42301131.

Bizjak-Suran et al. retrospectively analysed 439 adults referred for suspected dental material allergy who underwent patch testing with a local 24-allergen dental series. Half of patients had at least one positive reaction, with metals predominating. Nickel (23.0%) and palladium (16.6%) were the most common allergens. Methacrylate allergy was less frequent (6.2%) but reliance on HEMA alone would have missed over 40% of methacrylate-positive patients, with HPMA providing important additional diagnostic yield. Tin was not included in the series. Notably, almost 19.8% reactions were detected only on day 6/7. The findings support comprehensive dental series and suggest late readings detects additional sensitized patients.

Alkyl Glucosides in Rinse-Off and Leave-On Cosmetics Available on the Dutch Market

Yaâkoubi M, Ipenburg NA, Groot AC, Rustemeyer T. Contact Dermatitis. 2026 Jun 14. doi: 10.1111/cod.70200. PMID: 42289776.

In this Dutch study, 650 cosmetic products were assessed for the presence of alkyl glucosides. Nearly half (47.3%) of rinse-off products contained at least one alkyl glucoside, particularly baby shampoos, shower gels and baby shower gels (56–62%), while around one in five leave-on products (excluding lip balms) also contained these ingredients. Coco-glucoside predominated in rinse-off formulations, whereas cetearyl glucoside was most common in leave-on products. Given the substantial co-reactivity between alkyl glucosides, the authors suggest that sensitised patients avoid all products containing this class of surfactants. The findings reinforce the importance of checking ingredient labels and considering alkyl glucosides in patients with persistent cosmetic-related allergic contact dermatitis.

We are pleased to announce this year’s recipients of the Best SpR Presentation and Best Poster Presentation awards for work presented at the British Association of Dermatologists (BAD) Annual Meeting 2026.

Best SpR Presentation

Joint winners:

• Dr Romina Golchin – “Assessment of Diabetic Glucose Monitors using GC-MS”
• Dr Yasmin Khan – “The Fine Print in Topical Anti-Inflammatories: Excipient Exposure in Topical Corticosteroids and Calcineurin Inhibitors”

Best Poster Presentation

• Dr Zara Ali – “Paraphenylenediamine allergy: a seven-year retrospective audit of patch test findings, patient outcomes, and the safety of ‘PPD-free’ products”

Congratulations on this well-deserved recognition. We also thank everyone who presented, attended, and contributed to another successful Annual Meeting, helping to showcase the breadth and quality of dermatology research and practice.

The BSCA is holding a one-day, in-person course for trainees in partnership with the Royal Society of Medicine (RSM) Dermatology Section. Sessions will be delivered by national experts in contact dermatitis through a combination of lectures, interactive sessions, and practical workshops. 

Date: Thursday 17th September 2026 (9am to 6pm)

Location: Royal Society of Medicine, London

Registration fees for residents:

• Free for RSM members (optional lunch: £35.75)
• non-RSM member: £195

Who should attend?

• Dermatology resident doctors at all stages of higher specialist training, pre-accreditation 
• Dermatology resident doctors seeking to develop practical patch testing skills mapped to curriculum requirements 
• Those preparing for or currently undertaking contact dermatitis clinics in their training posts

Registration is via the RSM website: https://www.rsm.ac.uk/events/dermatology/2025-26/deu12/

• Term: 6 years (eligible for re-selection)
• Involves attending committee meetings and contributing to activities
• Up to two representatives per region

Dear members,

Summarised below are four recent publications regarding findings from patch testing in older patients, photopatch testing and observations on testing to DPG as well as a case report on ACD to hydroquinone.

Hydroquinone Allergic Contact Dermatitis: Widening the Potential Dangers of Black Henna Tattoos.

Bridgewater K and Stone NM, Contact Dermatitis. 2026: 1–3

This case report of hydroquinone contact allergy (used in a combination cream with tretinoin 0.025% and fluocinolone acetonide 0.01% for melasma, purchased through an online personalised prescription skin service) in a patient with a history of severe p-phenylenediamine (PPD) allergy. Patch testing was positive to both hydroquinone and tert-butylhydroquinone as well as strong positive to the product itself. The authors raised the possibility of cross-reactivity between hydroquinone and PPD via the shared metabolite benzoquinone. As access to hydroquinone through online skincare services increases, dermatologists may wish to enquire about previous black henna tattoo or hair dye reactions before prescribing hydroquinone-containing products.

Forgotten Skin: What do our geriatric patch test findings reveal?

Gorgulu Akin B, Kalkan F, Maden S, Bayrak Durmaz M S, Ozdel Ozturk B, Burak Kursun M, & Soyyiğit S. Allergologia Et Immunopathologia. 2026. 54(3), 87-95.

This retrospective patch test study analysed 128 patients aged ≥65 years patch tested with the European Standard Series (ESS). Only 22 patients were ≥75 years of age. Preservatives, fragrances and propolis were the most common contact allergens identified. In patients aged 65–74 years, propolis (20%), fragrance mix I (17%), methyldibromo glutaronitrile (16%) and Peru balsam (15.1%) predominated, whereas MCI/MI (22.7%) was the leading allergen, followed by MI, propolis, and textile dye mix (all 13.6%) in those aged ≥75 years. In both groups, the hands were the most frequent site for allergic contact dermatitis. The prevalence of propolis was postulated to be due to exposure from topical formulations. Positive reactions were less frequent and generally weaker in the older age group, supporting the concept of immunosenescence and diminished T cell responsiveness in advanced age. The findings highlight the continued value of patch testing in older adults and suggest that allergen profiles differ with advancing age.

Prospective Multi-Centre Photopatch Test Study of Photoallergy to Sunscreens and NSAIDs in Europe.

Ralph N, Goossens A, Carrascosa JM, Goncalo M, Wulf HC, Calzavara-Pinton PG, Rhodes LE, Wilkinson M, Bourke J, Eadie E, Moore E, Christou E, Ibbotson SH. Br J Dermatol. 2026 Mar 28:ljag085. doi: 10.1093/bjd/ljag085.

In this prospective multicentre European study, photopatch testing identified photoallergic reactions to sunscreen chemicals in 10% of patients and to topical NSAIDs in 9%. The most common photoallergens were ketoprofen, promethazine, avobenzone (butyl methoxydibenzoylmethane), oxybenzone (benzophenone-3) and etofenamate. No positive photoallergic ACD was detected in patients with chronic actinic dermatitis (CAD). A key methodological finding was that a 24-hour occlusion period before UVA irradiation missed 53% of sunscreen photoallergic reactions and 36% of NSAID photoallergic reactions compared with a 48-hour occlusion. Whilst the topical photoallergens seem relatively stable in nature, the authors recommend a 48-hour occlusion period prior to irradiation to optimise the diagnostic yield of photopatch testing.

Allergic Contact Dermatitis to 1,3-Diphenylguanidine Over a 23-Year Period: Recent Cases Involve Sterile Polyisoprene Gloves.

Brasher TR, Palmer A, Nixon RL. Contact Dermatitis. 2026 May 8. doi: 10.1111/cod.70178. Epub ahead of print. PMID: 42099181.

In this retrospective audit of 2675 patients patch tested between 2002 and 2024, 1.9% had positive reactions to 1,3-diphenylguanidine (DPG), a rubber vulcanisation accelerator. Of these, 31 (62%) were diagnosed with clinically relevant allergic contact dermatitis (ACD). Patients with DPG ACD were more likely to be male, aged over 40 years, have occupationally related dermatitis, and present with hand involvement. Gloves and footwear were the most common exposure sources, with over half of the relevant cases linked to gloves. Notably, the four most recent cases involved healthcare workers exposed to sterile polyisoprene gloves, presenting with predominantly dorsal hand dermatitis and paronychia. The authors conclude that DPG remains an important cause of occupational ACD, particularly in healthcare settings, and highlight sterile polyisoprene gloves as a potential source of exposure that should be considered during patch testing and workplace investigations.

Dear members,

A new corticosteroids information sheet is now available on the Patient Information Leaflets section of the BSCA website.

• Term: 6 years (eligible for re-selection)
• Involves attending committee meetings and contributing to activities
• Up to two representatives per region

Dear members,

The patient information leaflet (PIL) Update Group have created a new information sheet on carvone as well as updated several information leaflets (DMPA, cocamidopropyl betaine, PPD).  These can all be found on the Patient Information Leaflets section of the BSCA website.