Pimple-like rash?

I keep getting this pimple-like rash all over my chest.  It can show up anywhere from the top of my breasts to right below where my neck starts, and it often gets so bad that it covers that entire area, with literally hundreds of little red pimples (many with white heads).

I have been dealing with this since I was 17 years old,  and I am now 25.  It is much, much worse when I am living in a place with city water.  When I have well water, I might have some minor flare ups, but just using a benzoyl peroxide mask once or twice a week keeps my skin completely clear.

When I live somewhere with city water though, it doesn't matter what I use.  I will break out, and it starts out as a patch or two of dozens of pimples - but then it spreads.  I can use benzoyl peroxide or sulfur creams, and completely dry all of my skin out, but it doesn't affect the pimples much  Once it starts, if I don't manage to fix it with acne cream (which I have very mixed results with, even in the beginning), it will spread and not go away.

I had this rash for several months back at my old apartment, and nothing would even make it clear up a little bit.  Then, as soon as I moved back to my parents' home with well water, it cleared completely up within a week.  I just moved to a new city about a month ago, and I'm struggling with this problem again.

I am so upset.  I can't wear anything other than crew neck and turtleneck shirts - and even with crew necks, the pimples sometimes still show.  Like I said, it starts out in a couple of patches of pimples or so, and then it spreads like wildfire.  Weirdly enough, my face does not really break out much, and when it does, I just get a normal pimple or two.

I have tried all types of shower filters, including those that claim to break down the chloramines in the water.  I know that I need to go the dermatologist, but I just started a new job and do not have health insurance yet.

Is this even acne?  What can I do at this point?  

[Bhupinder Kaur, MD]

Hello,
It can be due to chest acne or folliculitis skin. Thoroughly wash your body everyday, especially the back and chest part using a back brush and frequently change your bed sheet, as it is conducive for bacterial growth. Engage in a diet that is low in sugar and fat but is rich in vitamins. This prevents acne by preventing the buildup of excess oil on the skin. Also refrain from touching or squeezing your acne. Also try to keep your hair free of dandruff by using good antidandruff shampoos. You can also apply benzoyl peroxide creams or clindamycin cream on the acne.

Other treatment options include topical retinoids, hormonal therapy, dermabrasion , phototherapy and laser resurfacing. Normally a combination of treatments is followed and if nothing proves effective then dermabrasion and laser therapy are useful. You can discuss these treatment options with your dermatologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.