Contact allergy to capryloyl salicylic acid

Contact allergy to capryloyl salicylic acid: a mechanistic chemistry and structure–activity perspective

“…Our overall conclusion is that 5‐CSA itself is unlikely to be significantly allergenic, and is therefore unlikely to be the cause of the contact allergy reported by de Groot et al . However, the isomer 3‐CSA is a highly plausible contaminant of 5‐CSA, and is likely to be sufficiently allergenic to account for the observed contact allergy.…”

“…Both 3 and 4 are phenolic esters, and as such are likely to be reactive enough to sensitize by the acyl transfer mechanism . However, we consider it unlikely that either 3 or 4 is responsible for the contact allergy observed by de Groot et al , for two reasons. First, the aluminium trichloride‐catalysed O‐acylation reaction is reversible, so although 3 may be formed early in the process, and indeed is probably the initial reaction product, under the Friedel–Crafts reaction conditions it will be converted to the more thermodynamically stable C‐acylation products 2 ( Fig.…”

“…de Groot et al have reported contact allergy, in 2 patients, to capryloyl salicylic acid (5‐CSA, 1 , CAS no. 78418‐01‐6), also known as 2‐hydroxy‐5‐octanoylbenzoic acid, which is used as a skin conditioner in various cosmetic products . The structure is shown in Fig.…”

New Cosmetic Contact Allergens

“…Contact allergy to ethylhexylglycerin (synonyme: octoxyglycerin), another widely-used skin conditioning agent, has been reported several times in the literature, the most recent case concerning its presence in sunscreens [49]. Recently, two cases of contact allergy to capryloyl salicylic acid were described as well [50].…”

2‐Hydroxyethyl methacrylate (HEMA): A clinical review of contact allergy and allergic contact dermatitis. Part 2. Cross‐ and co‐sensitization, other skin reactions to HEMA, position of HEMA among (meth)acrylates, sensitivity as screening agent, presence of HEMA in commercial products and practical information on patch test procedures

“…In part 1 of the article, the epidemiology of HEMA contact allergy was discussed and detailed information on published case series and case reports was presented. It was found that HEMA is currently an important cause of contact allergy and ACD in North America and Europe with recent prevalences of 3.2% in the United States + Canada 1 and 1.5%–3.7% In Europe 2 . The rising importance of HEMA as a cause of ACD in Europe was well noted and, therefore, in January 2019, the European Society of Contact Dermatitis included HEMA in the European baseline series for routine testing 3,4 .…”