Sorbitan Sesquioleate, a Common Emulsifier in Topical Corticosteroids, Is an Important Contact Allergen

Background: In the past, sorbitan sesquioleate (SSO) was reported as an uncommon allergen, but recent data suggest SSO may be an important sensitizer. Objective: To present data on 13 of 112 dermatitis patients who reacted to SSO and/or sorbitan monooleate (SMO) on patch testing. Methods: A retrospective data analysis was conducted on data from 112 dermatitis patients patch-tested from December 2006 to May 2007. All patients were tested with a modified North American Contact Dermatitis Group standard series, a cosmetic series, and a fragrance series. Results: Of 112 patients, 10 (8.9%) reacted to SSO, 1 (0.9%) to SMO, and 2 (1.8%) to both. Nine of 12 (75%) SSO-positive patients were using topical corticosteroids emulsified with sorbitan derivatives or sorbitol; 2 of the 13 sorbitan-allergic patients were allergic to one or more corticosteroid screening chemicals tested. Conclusion: SSO is a common emulsifier derived from sorbitol and is used in many high- to super-potent corticosteroids. It has only recently been identified as an important contact allergen. The high prevalence of reactions to sorbitol derivatives in this small group of patients suggests that these chemicals may be sensitizing when applied to dermatitic skin. Larger studies should be conducted to confirm these findings.