I had been struggling with bacne for about six months and in the depths of despair when I visited a dermatologist about 5 weeks ago. I was prescribed the antibiotic Erythromycin (as I am allergic to Doxycycline, the other common antibiotic for acne), a one-month course. I also took a small dose of antihistamines (Atarax, 1/3 of a tablet three times a day) since it seemed that my acne would flare up after meals, and I had some suspicion it could be allergy to something in the food I'm allergic to.
(This was just a suspicion of mine, as an IgG food test panel showed negative allergy to the common foods and my dermatologist pointed out that food allergies usually manifest in eczema or rashes rather than acne.)
After reading the treatment regimes on acne.org, I threw out my Johnsons pH 5.5 cleanser that contained Sodium Laureth Sulphate and swtiched to Cetaphil's Gentle Skin Cleanser. I cleansed my body twice a day with it.
Flash forward to now, five weeks later -- the active acne spots are all gone, finally, and I'm just left with the scars from previous inflamed acne spots. I never thought I would see my back acne-free... not spotless yet, but the scars have lightened considerably and I'm just going to give them time to fade. I was tempted to try some suggestions for scar-fading creams, gels etc but honestly, am afraid to rock the boat since for the first time in many frustrating months, my skin is finally stablizing.
My dermatologist put me on another two months of Erythromycin to be safe, which I'm continuing with. Hopefully in two months, this bacne will be a distant memory with little evidence left on my skin.
During my first appointment, dermatologist also gave me an acne spot topical lotion which contains Clindamycin. it works wonders for little pimples that have just appeared on the skin -- I just apply it twice a day, and the pimple etiher dries up on its own or comes to the surface and is easy to burst and clean with minimal squeezing and usually heals with hardly a scar.
Just wanted to share my experience so far. Different things work for different people as the root causes of acne vary, but if you haven't tried antibiotics, it could help if your acne is bateria-related. Different families of antibiotics can have different reactions -- for me, the "~mycin" family of antibiotics worked well for me (both oral and topical) while the "~cycline" one made me break out in hives and rashes.
Also, like many others on this forum, I highly recommend Cetaphil Gentle Skin Cleanser. My skin immediately calmed down within the first few days of using it -- perhaps the SLS in my previous body cleanser aggravated the acne.