Signs of infection after vaginal abrasion and how possible is yeast infection after?

Genital ulcer?: If "abrasion" means there is a vaginal sore of any kind, see a doctor. The most common cause of new genital ulcer is herpes, even when the apparent cause is injury during sex, like an abrasion. And herpes sometimes causes symptoms similar to yeast. Maybe it's just minor trauma plus yeast, but best not to take chances. Check it out.