What Do You Do For A Spider Bite That Has

what do you do for a spider bite that has been on my wifes ankle for about 18 months? Blood tests, antibiotics, topical gels? it itches and real red. she was putting baking soda/H2o mixture on it and was drying it up some. Then, her friend convinced her to put bleach on it and she about jumped through the roof! Now it looks almost purple! not red. Any ideas? she doesn't know what species spider it was, but says it has two fang marks.