Patch testing procedures in patients suffering from suspected allergic contact dermatitis to minoxidil
January 1989
TLDR Allergic reactions to minoxidil may be due to the propylene glycol it is mixed with, not the minoxidil itself.
The study examined two patients with androgenetic alopecia who developed allergic contact dermatitis after using Regaine® solution. Patch testing revealed that the dermatitis was not caused by minoxidil itself but by the vehicle propylene glycol in which minoxidil was dissolved. The study concluded that when testing for minoxidil allergies, it is crucial to consider the vehicle used, as the choice of vehicle can significantly impact the test results.
