CD01: The ‘extended’ facial series audit: recommendation to include shellac and sodium benzoate in the British Society of Cutaneous Allergy Facial Series

Orals

Sophie Rolls,¹ Deirdre Buckley,² Mahubub M.U. Chowdhury,³ Simon Dawe,⁴ Catherine Holden,⁵ Faheem Latheef,⁶ Avad Mughal,⁷ Birgit Pees,⁸ Asha Rajeev,⁹ Ruth Sabroe,⁵ Livia F. Sorano,⁸ Donna Thompson,¹⁰ Heather Whitehouse,⁶ Mark Wilkinson⁶ and Natalie Stone¹

¹The Royal Gwent Hospital, Newport, UK; ²Royal United Bath Hospital, Bath, UK; ³Cardiff and Vale University Health Board, Cardiff, UK; ⁴West Hereford NHS Trust, Hereford, UK; ⁵Sheffield Teaching Hospital NHS Trust, Sheffield, UK; ⁶Leeds Teaching Hospital NHS Trust, Leeds, UK; ⁷Neath and Port Talbot Hospital, Port Talbot, UK; ⁸University Hospital Southampton NHS Trust, Southampton, UK; ⁹East Kent Hospital University NHS Trust, Kent, UK; and ¹⁰Sandwell and West Birmingham Hospital NHS Trust, Birmingham, UK

The British Society of Cutaneous Allergy (BSCA) updated the BSCA facial series in 2019. Seven allergens of undetermined importance were identified and were not included on the 2019 updated BSCA facial series. The BSCA proposed further assessment of the relevance of these seven allergens, and created an ‘extended series’, including butylated hydroxytoluene (BHT; 2,6-di-tert-butyl-4-cresol) 2% pet.; butylhydroxyanisole (BHA; 2-tert-butyl-4-methoxyphenol) 2% pet.; dimethyl dimethylol (DMDM) hydantoin 2% aq.; ethylhexylglycerin 5% pet.; methoxybenzophenone (benzophenone 3, oxybenzone) 10% pet.; shellac 20% alc.; and sodium benzoate 5% pet. We audited data from 10 UK patch test centres on this extended series over the 12-month period between October 2020 and September 2021. We calculated the rate of positive patch tests to each allergen. A 0·3% positive rate was defined as the threshold to warrant inclusion of an allergen in the facial series, the same threshold that had been used when updating the BSCA Facial Series. The total number of patients tested to each allergen ranged from 1457 (shellac) to 1948 (BHT). The positive rate for each allergen was: BHA 0·2%; BHT 0·2%; DMDM hydantoin 0·2%; ethylhexylglycerin 0·0%; methoxybenzophenone 0·0%; shellac 0·5%; and sodium benzoate 1·5%. BHA, BHT and DMDM hydantoin had positive patch test rates just below the inclusion threshold. Shellac and sodium benzoate had a positive pick-up rate > 0·3%. Relevance was found in 43% of patients with a positive patch test to sodium benzoate, including Aveeno® and Sanex® body washes and Palmer’s® Coconut Oil Formula Body Lotion. This audit of the extended facial series demonstrates the importance and relevance of shellac and sodium benzoate, each of which was positive in > 0·3% of those selected for testing. Shellac 20% in alcohol also has irritant potential. Reading ingredient labels and additional patch testing with patient’s own products are both important, to ensure that positive results have clinical relevance. We recommend the addition of shellac and sodium benzoate to the BSCA Facial Series.