# 2‐Hydroxyethyl Methacrylate, Methyl Methacrylate and Ethyl Acrylate Sensitisation: A 7‐Year Retrospective Study

## TL;DR

This study examines sensitization to three acrylates in Hungary, finding that testing all three improves diagnosis and is linked to nail product use, especially in young women.

## Contribution

The study is the first in Europe to include MMA and EA alongside 2-HEMA in standard patch testing, revealing new insights into acrylate sensitization patterns.

## Key findings

- 3.7% of patients showed sensitization to at least one acrylate, predominantly in women.
- 20.3% of acrylate-positive patients reacted only to MMA and/or EA, not 2-HEMA.
- Delayed reactions to MMA were detected on the 7th day, highlighting the need for extended testing.

## Abstract

Acrylates are increasingly common contact allergens; sensitisation is frequently associated with nail products. No prior study has been found in the European literature in which both methyl methacrylate (MMA) and ethyl acrylate (EA), in addition to 2‐hydroxyethyl methacrylate (2‐HEMA) were included in the standard baseline series.

To investigate the prevalence and characteristics of 2‐HEMA, MMA and EA sensitisation at a university centre in Hungary.

This retrospective study included 2005 consecutive patients who underwent patch testing between 2018 and 2024 with the European baseline series (EBS) extended with 2‐HEMA (in 2018), MMA and EA.

Out of the tested 2005 patients, 74 (3.7%) were positive for at least one of the three acrylates; among them 86.5% were women. Mostly the hands (70.3%) and the face (24.3%) were symptomatic. Nail product exposure was significantly more frequent among younger patients. 20.3% of the acrylate‐positive patients had no hypersensitivity to 2‐HEMA, only to MMA and/or EA. Reactions to 2‐HEMA and EA mostly appeared on D2, whereas MMA first reactions were predominantly on D7.

Our findings suggest that testing MMA and EA in the EBS would be beneficial. Evaluating patch tests until the 7th day is essential.

In our cohort acrylate hypersensitivity was associated with using of artificial nail products (mainly young women). Reading the test until the 7th day helps to avoid missing delayed reactions (mostly by MMA). Testing 2‐HEMA exclusively would have resulted a loss of 20% of the sensitisations, it is worth testing 2‐HEMA + MMA and EA to improve diagnostic accuracy.