CD02 A retrospective comparison of Chemotechnique Cosmetic series–positive contact allergens with the British Society for Cutaneous Allergy facial series

Abstract

Abstract Patch testing is an important tool in the assessment of facial dermatitis. The cosmetic or facial series of haptens are highly relevant in facial dermatitis. The British Society for Cutaneous Allergy has recently updated the facial series to include the reduced number of 24 haptens. We compared positive allergens found in the Chemotechnique Cosmetic series (60 haptens) with that of the British Society for Cutaneous Allergy (BSCA) facial series. We conducted a retrospective review of patients who were patch tested to the Chemotechnique Cosmetic series over a 30-month period. We recorded and compared positive contact allergens in this series with that of the BSCA facial series. Sixty-three patients were patch tested to the Chemotechnique Cosmetic series over a 30-month period. Twenty-one patients were diagnosed with at least one positive contact allergen. In total, 35 contact allergies were diagnosed. Contact allergen positivity was seen to sorbitan oleate (Span 80; positive rate 4.7%), thimerosal (Merthiolate; positive rate 4.7%), chloroacetamide (positive rate 4.7%), hexahyrdo-1,3,5-tris(2-hydroxyethyl) triazine (Groton BK; positive rate 4.7%), abitol (hydroabietyl alcohol; positive rate 9.5%), benzophenon-3 (Eusolex® 4360, EscalolTM 567, oxybenzone; positive rate 4.7%), sorbitan sesquioleate (positive rate 14.2%), benzyl salicylate (positive rate 9.5%), tert-butyl hydroquinone (positive rate 14.2%), tea tree oil oxidized (positive rate 4.7%), 3-(dimethylamino)-1-propylamine (positive rate 4.7%), Amerchol (positive rate 4.7%), quaternium (positive rate 4.7%), methyldibromo glutaronitrile (MDBGN; positive rate 9.5%), methylisothiazolinone (MI; positive rate 4.7%), sodium metabisulfite (positive rate 28.5%) and gallate mix (positive rate 28.5%). Nine patients (43%) were found to have more than one contact allergy. Five of the positive haptens (Amerchol, quaternium, MDBGN, MI and sodium metabisulfite) are captured within the BSCA standard series but are not found within the BSCA facial series. Benzophenone 3 is captured within the BSCA extra facial series. Five further haptens [sorbitan oleate (Span 80), thimerosal (Merthiolate), chloroacetamide, hexahyrdo-1,3,5-tris(2-hydroxyethyl) triazine (Groton BK) and benzyl salicylate] were captured with the Chemotechnique series. However, these five are not included in the BSCA facial series and would not otherwise have been identified. Seventeen per cent of contact allergies would not have been diagnosed in this study if the BSCA facial series had been applied. This study highlights the variation in positivity seen between the Chemotechnique and BSCA facial series and the potential for missed diagnoses.