Occupational Airborne Allergic Contact Dermatitis From <scp>UV</scp> ‐Curing Printing Varnish

Acrylates have repeatedly been reported as sensitizers in ultraviolet-curable ink. We report a case of severe occupational airborne allergic contact dermatitis caused by acrylate-containing varnish. A 44-year-old woman with a history of atopy, including atopic dermatitis and respiratory allergy to pollen was referred to the dermatology and allergology department for a severe skin eruption. In December 2024, she developed a lesion on her upper eyelids, which subsequently became bilateral, affecting both upper and lower eyelids. In the following months, erythematous eruption appeared progressively on the dorsal surfaces of the hands, anterior wrists and anterior cervical region. Treatment with desonide 0.05% was effective on the face; however, the lesions relapsed shortly after discontinuation. By May 2025, the clinical presentation was suggestive of airborne allergic contact dermatitis (Figure 1). During the clinical interview, several potential contact allergens were identified, appearing after a relocation in November 2024 involving construction work and the use of paints. The patient also reported exposure to household detergents, essential oil-based products, cosmetics, and makeup. Additionally, she had recently switched to photopolymerizable ink and varnish at her workplace, where she had been working as a graphic designer for 3 years, creating signs, flyers and posters. However, the workplace exemption test was negative, likely because she had only been off work for 1 week. The exact composition of the ink was initially unknown, but acrylates were suspected due to the light-curing properties reported by the patient. Given the high prevalence of allergic contact dermatitis in the printing industry, an occupational origin was strongly suspected—especially considering the airborne distribution of the rash and the well-known potential for acrylates to cause allergic contact dermatitis [1]. Following the initial consultation, the patient independently performed a semi-open test with UV ink as is applied directly on her belly for 2 h. On Day (D) 2, a non-irritant positive reaction was observed (Figure 2). Patch tests were performed with the European baseline series, cosmetic series, acrylate series and epoxy series (Chemotechnique Diagnostics, Vellinge, Sweden), varnish 1% petrolatum (pet.) and ink 1% pet according to published recommendations [2]. Patch test chambers used were IQ ultra (Chemotechnique Diagnostics, Vellinge, Sweden) for 2 days. Readings performed on D2 and D3 (Table 1). Nickel sulfate 5% pet (++) Myroxylon pereirae 25% pet (+) Nickel sulfate 5% pet (++) Myroxylon pereirae 25% pet (++) On D3, patch tests were positive (+) for varnish, ink (Figure 3) and 1,6-Hexanediol diacrylate 0.1% pet. Patch test with nickel sulphate was also positive (++), with former relevance due to prior reactions to costume jewellery. Patch test with Myroxylon pereirae was positive (++) but its relevance was unknown. The material safety data sheet collected afterwards confirmed the presence of 1,6-Hexanediol diacrylate in the varnish (Additional File: produit-uv-ink and produit-varnish), confirming the diagnosis of occupational airborne allergic contact dermatitis. Following the tests, the patient underwent a work leave, resulting in complete healing of the lesions after 3 weeks. A certificate of occupational disease was issued according to Table no. 65 of the French social security system. Acrylates are widely used in the printing industry as monomers and prepolymers in UV-curable inks and overprint varnishes. Their rapid polymerisation under UV light makes them highly effective for fast-drying applications. Several cases of contact allergy to acrylates in this industry have been reported [3-7]. In our case, 1,6-Hexanediol diacrylate (1,6-HDDA), a highly sensitising diacrylate monomer, was identified as the culprit allergen in the varnish. This finding aligns with prior reports highlighting HDDA as a frequent allergen in UV-curable products [7]. While the specific allergen responsible in the ink was not definitively identified, suspicion fell on 1,6 HDDA due to the presence of acrylic ester listed in the material safety data sheet. This underscores the challenge of identifying causative agents in complex industrial mixtures, where patch test with relevant workplace materials is critical. Interestingly, no cross-reactivity was observed among the various acrylates tested in our patient. It is also important to note that 1,6-HDDA is found in coatings, adhesives, health products, and clothing materials, which broadens the range of potential sensitization sources [8-10]. In our patient's case, sensitization was occupational, with no other sources of exposure identified. A limitation of our case report is that, although a 1% dilution of the patient's own product was used, no dilution series or control group testing was performed. Additionally, the absence of a Day 7 reading should be noted, as such measures are important to exclude irritant reactions and detect delayed onset reactions. Finally, the short duration of work absence was insufficient for complete healing of the lesions. This case illustrates the importance of testing with the workplace allergens to guide appropriate management. Magalie Coco-Viloin: conceptualization, investigation, writing – original draft, writing – review and editing. Caroline Gernigon: review. Fabrice Herin: review and validation. Open access publication funding provided by COUPERIN CY26. The authors declare no conflicts of interest.