He has fowl pox. I would keep him quarantined especially knowing your hen had coryza, if there were bird to bird contact with your hen or droplets from sneezing etc, you're rooster most likely has it or will have it. It depends on the incubation time of the disease.
Quote:
Infectious coryza is contageous and birds remain carriers for life. Here's a link, scroll down to infectious Coryza:
http://edis.ifas.ufl.edu/ps044