Can a yeast infection cause a small bump?

Usually not...: A yeast infection presents with vaginal itching, burning sensation, whitish and sometimes yellowish discharge most of the time looking like cottage cheese or flaky. If you have lesions that are itchy, painful and started in the form of blisters it could be herpes, but don't panic boils can present with painful bumps as well. I would suggest that you see your GYN provider for a definite diagnosis.