Recommendation to include hydroxyethyl (meth)acrylate in the British baseline patch test series.

Area of Science:

• Dermatology
• Allergology
• Toxicology

Background:

• (Meth)acrylates are common causes of allergic contact dermatitis (ACD), with increasing incidence linked to acrylic nail demand.
• Current UK and European baseline patch testing protocols do not routinely include (meth)acrylates.
• Preliminary data suggest a high rate of positive patch tests for (meth)acrylates in patients with relevant exposure history.

Purpose of the Study:

• To evaluate the efficacy of including 2-hydroxyethyl methacrylate (2-HEMA) 2% in petrolatum in the baseline patch test series for detecting treatable (meth)acrylate ACD.
• To assess the diagnostic yield of 2-HEMA as a marker for broader (meth)acrylate allergy.

Main Methods:

• A multi-centre study in 15 UK dermatology centres from 2016-2017.
• Inclusion of 2-HEMA in the extended baseline patch test series for 5920 patients.
• Selective patch testing with eight (meth)acrylate allergens for patients with suspected exposure or positive 2-HEMA results (669 patients).

Main Results:

• 1.7% (102/5920) of patients tested positive to 2-HEMA.
• 2.4% (140/5920) tested positive to at least one (meth)acrylate.
• Excluding 2-HEMA would have missed 0.6% (36/5920) of all patients with (meth)acrylate allergy. Top allergens: 2-HEMA (1.7%), 2-hydroxypropyl methacrylate (1.0%), 2-hydroxyethyl acrylate (1.0%).

Conclusions:

• Routine inclusion of 2-HEMA 2% petrolatum in the UK baseline patch test series is recommended.
• A standardized short (meth)acrylate series is suggested to improve detection of (meth)acrylate allergy.
• This strategy will enhance the diagnosis and management of (meth)acrylate-induced ACD.