Back acne

Always had mild facial acne prior to pregnancy and I was on tretinoin, but had to stop once I found out i was expecting. Currently 19 weeks and my back acne is growing out of control. I never had acne on my back, just one pimple prior to getting my period. Now when I touch my back (what i can reach lol) I feel 2-3 pimples. My shoulders/traps have pimples but they cant really be popped. Any acne body wash recommendations? I know i shouldn't care but I fear its only going to get worse and uncontrollable post pregnancy:(