ABSTRACT
Minoxidil is converted into its active metabolite minoxidil sulfate by sulfotransferase enzymes. The data presented in the chapter suggest that contact allergy to/allergic contact dermatitis from minoxidil is relatively frequent. Minoxidil (2% alcohol) was tested in 62 patients and there were 22 positive reactions to it. Of 161 patients participating in a clinical trial of treating common baldness with 2% minoxidil lotion for at least 2 years, 6 (3.7%) developed allergic contact dermatitis. The data presented in this chapter suggest that contact allergy to/allergic contact dermatitis from minoxidil is relatively frequent. In Leuven, Belgium, in the period 1990-2014, iatrogenic contact dermatitis was diagnosed in 2600 individuals (17% of the total patch test population). 96% of all positive patch test reactions to topical drugs and antiseptics were considered to be relevant. Minoxidil (2% alcohol) was tested in 62 patients and there were 22 positive reactions to it.
