A dermatologist will most likely recommend some sort of a drug like tetracycline or some of the newer once. Be careful with drugs, first try what other folks here have already recommended.
Many times eliminating allergy causing foods will resolve skin conditions. Eliminate one food group at a time, then see what happens. Common allergens: milk and all its products, soy, wheat, fish/seafood, etc

try tea tree oil it works quite well and isn't that expensive

I second the tea tree oil. It also works on insect bites.

My kids both went to a dermatologist when they reached the acne age, and had very few zits.

A friend says that when he was that age he used Witch Hazel on his face, it dried everything up and he had few.

Guys seem to have a harder time with acne thanks to shaving. When I was a teenager I didn't have all that many zits, but I got ingrown hairs like crazy.

Good luck...

wheat grass?? I never heard of it. <img src="/images/graemlins/ooo.gif" alt="" /> I will investigate it. this is really dicy. It sounds like a scam to me. hmm.