Propylene glycol: an often unrecognized cause of allergic contact dermatitis in patients using topical corticosteroids.

Propylene glycol (PG) is considered to be a ubiquitous formulary ingredient used in many personal care products and pharmaceutical preparations. It is an organic compound commonly found in topical corticosteroids (CS). Cutaneous reactions to PG are mostly irritant, but allergic contact dermatitis to PG is well-documented. Cosensitization to PG and topical CS can occur, making it challenging to choose the appropriate topical CS in a PG-allergic patient. This review is aimed at guiding clinicians in the selection of a suitable topical corticosteroid when presented with patients allergic to PG.