He was notorious as a womanizer and whoremaster and was derided by fellow, more pious and traditional mafiosi, as nothing more than a pimp. I thought it was interesting to show him getting treated for a venereal disease because there's a famous story of how he got revenge on one of the guys who beat and cut him and gave him that droopy eye he had. They took a rag, wiped it on a dirty hooker's venereal vajayjay and smeared it all in this guy's eyes. Blinded the poor bastard.

Also, Al is about 2 years away from getting the syphillis that eventually kills him. As evidendced by the dentist's office and Lucky's gonorrhea treatment, medicine was prehistoric just 80 years ago.