Does Itching Rash On Vagina Indicate Yeast Infection?

i have a rash on my vagina. I also have slight itching at the entrance of my vagina. Just finished a course of antibiotics for sinusitis. itching feels like a yeast infection, but have never had a rash. Is this a yeast infection?

Age 50 150lbs, 5ft 6 in hypertensive