Some individuals who use minoxidil solution develop itching in the scalp. In most cases, this is not due to an allergy to the minoxidil but rather due to irritation from a chemical that is mixed with the minoxidil. This chemical is called propylene glycol. If patients have a lot of itching with minoxidil, a minoxidil formulation that does not contain propylene glycol can be recommended. A common example of a proplylene glycol free product would be minoxidil 5% foam or minoxidil compounded by the pharmacist in glycerin, water and ethanol.
Very rarely, a patient can be truly allergic to minoxidil. Specialized allergy testing performed by a dermatologist (called patch testing) can help to determine if a patient is actually allergic to minoxidil. Usually such testing is only performed in complex or challenging situations.
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Vancouver office at 604.283.9299