Bad irritation on scalp and ears from Rogain- help

[lexer]

Hi guys
A few years back i was using rogaine foam and after2-3 weeks my scalp got very irritated and my ears were swollen and itchy. Doc said i may be allergic to rogaine.
Looking back, i may have been applying it to a wet scalp allowing much more absorption. Could that be a reason for the irritation? Also, is there anything specific to the foam itself that could cause this? Any other rogaine alternatives?
Thank you