Panthenol Allergic Contact Dermatitis: Sources of Exposure, Reported Cases, and a Call for More Frequent Testing.

Panthenol, a vitamin B5 derivative, is a key precursor in the synthesis of fatty acids that maintain epithelial function. Its ability to aid in moisturization, skin barrier restoration, and wound healing has led to its frequent incorporation into personal care products and pharmaceuticals-many of which are marketed to be hypoallergenic. While contact allergy to panthenol is rather uncommon, rates of positive reactions are on the rise, increasing from 0.2-0.7% to 1.2% in recent years. In this article, we discuss panthenol's chemical functionality and provide a list of commonly encountered gentle skin care products that may potentiate exposure. In addition, we include a review of the existing cases of panthenol-related allergic contact dermatitis and contact urticaria. Many of these cases involved initial positive reactions to a personal product tested "as-is," with subsequent testing of the individual constituents of these products revealing contact allergy to panthenol. These cases highlight the importance of testing for personal products and suggest potential utility in more routine patch testing to panthenol. Overall, the information presented aligns with several recent calls in the literature to test this allergen more frequently. As more consumers favor hypoallergenic skin care products, patch testing dermatologists may need to consider including panthenol in the baseline or extended allergen series. Furthermore, patients who transition to using hypoallergenic skin care products and continue to experience dermatitis symptoms may benefit from patch testing to panthenol.