That teacher is a nitwit. Can you imagine humiliating a young girl like that in front of her friends?
But yes, topical ointments (or lemon juice!) never work. Scrubbing your face doesn't work either, and can in fact aggravate the acne. Antibiotics and birth control pills usually don't work either. Accutane almost always DOES work, but it's hard on your liver, so you have to go in for lots of liver enzyme tests while you're on it. I think they only put you on it for a few months at a time. Also, there can be temporary side effects, like peeling, flaky, dry skin (especially on the lips and inside of the nose).
This is the reason the other treatments don't work: the problem lies with the texture of the sebum (oil) released by the pores. People with normal skin produce sebum that flows out of the sebaceous glands easily and spreads itself smoothly on the surface of the skin. Acne sufferers produce a thicker, stickier sebum, that clogs up more easily with dirt and causes inflammation and infection. Sex hormones, and especially fluctuating hormones, can cause the skin to produce more sebum. If you've got normal skin to start with, the overactive sebaceous glands may cause a few zits (i.e. mild acne) but it tends to settle down as the hormones do, once you're through puberty. That's why mild acne can be treated with keeping your face clean, using benzoyl peroxide topically, or even by taking birth control pills (which tend to even out fluctuating hormones). If you've got thicker sebum, though, the situation is already bad, hormones or no hormones. Puberty just makes an already difficult situation worse -- and what's more, the acne may not go away after puberty (and even if it does, it leaves scars). Accutane works by attacking the sebaceous glands themselves, so the skin produces far less oil. That's why your skin gets all dry while you're on it. It returns to normal once you're finished.
I would make an appointment with a dermatologist, not your regular doctor, to discuss all this.
P.S. I feel for your daughter! Best of luck with the doctor -- I'm sure they can sort it out.
