Sorry, I'm kind of late, but I'm glad the Benedryl worked, as it did look like hives, so my guess would be the egg too. Glad you gave him the Benedryl, it won't hurt them so anytime you think it may be an allergic reaction to something, give it to him.
Have a Great Bully Day.
Member of The Bulldog Club of America, The Bulldog Club of Texas and French Bulldog Club of America.
Bully hugs from - BeBe, Hazel, Lucy Lu, JLO, Hillary, Henri & Katie