Sensitisation to the acrylate co-polymers glyceryl acrylate/acrylic acid co-polymer, sodium polyacrylate and acrylates/C10-30 alkyl acrylate cross-polymer (Carbopol®) is rare.

BACKGROUND: Acrylate polymers and cross-polymers (ACPs) are frequently used cosmetic ingredients. The British Society for Cutaneous Allergy (BSCA) and the UK Cosmetic, Toiletry and Perfumery Association (CTPA) collaborated to investigate the allergenic potential of three commonly-used ACPs. OBJECTIVES: The objective of this study is to determine the prevalence of allergic contact dermatitis (ACD) to three ACPs: glyceryl acrylate/acrylic acid co-polymer, sodium polyacrylate, and acrylates/C10-30 alkyl acrylate cross-polymer (Carbopol®). MATERIALS AND METHODS: The BSCA prospectively audited data collected from 20 centres in the UK and Ireland between 1st September 2021 and 1st September 2022. Patients with suspected ACD to (meth)acrylates, with facial dermatitis, or consecutive patients, were patch tested to glyceryl acrylate/acrylic acid co-polymer 10% aqueous (aq.) sodium polyacrylate 2% aq., and to acrylates/C10-30 alkyl acrylate cross-polymer 2% aq. (Carbopol®). The frequencies of positive, irritant, and doubtful reactions were recorded. RESULTS: In total, 1302 patients were patch tested. To glyceryl acrylate/acrylic acid co-polymer, there was one doubtful reaction in a patient allergic to multiple (meth)acrylates, and one irritant. To sodium polyacrylate, there were four irritant reactions, one doubtful, and one positive reaction; in all cases, relevance was unknown and there was no demonstrable (meth)acrylate allergy. There were no reactions to Carbopol®. CONCLUSIONS: Sensitisation to these concentrations of the three tested ACPs is rare. Elicitation of dermatitis in (meth)acrylate-sensitised patients by exposure to these three ACPs appears unlikely.

Ideal proportion of the population to be patch tested: How many should we be doing?

BACKGROUND: How many patients should we be patch testing? A previous study suggested that the minimum proportion of a population to be patch tested for allergic contact dermatitis was 1:700 annually. OBJECTIVES: To evaluate if the current minimum rate for patch testing has changed over the 20 years since the previous study in order to maximize the value. METHODS: In cooperation with the British Society for Cutaneous Allergy, a proforma for collation of retrospective data between January 2015 and December 2017 was sent to patch-test centers in the United Kingdom (UK) and the Republic of Ireland (ROI). The number of positive tests was analyzed against the proportion of population tested to see what proportion of the population would yield the greatest number of positive results. RESULTS: Responses from 11 centers showed that the minimum number needed to patch test had increased to 1:550 per head of population per year using the current criteria. CONCLUSIONS: In agreement with previous studies, we should be patch testing more people than we are. We could reduce the threshold for referral of patients we patch test to derive the most benefit from this investigation.

Contact Dermatitis to Ophthalmic Solutions: An Update.

Eyelid and periorbital dermatitis remains a distressing and recalcitrant disease. Contact dermatitis remains the most common cause of eyelid and periorbital dermatitis. Ophthalmic solutions used in the treatment of ophthalmic conditions can often be the cause. This article is an update of our previous study, summarizing the contact allergens involved and the new test concentrations reported to investigate through patch testing. New insights found during the review are also documented.