I am a 23 year old male. I have had acne since I was 13. I was on Benzaclin for a good 2 years and then it stopped working. I had a full blown acne attack on my chest and face over the summer. I have severe cystic acne. I went to Dr. Jerald Sklar who is the best dermatologist in Dallas TX. He prescribed me Differin, Dorryx, Clindamycin. I use differin and take the Dorryx pill at night and apply clindamycin in the morning. I have been following this treatment religiously for one month now. I see some improvements on my face but not on my chest. Anybody know how long it will take until all of the acne clears up???