Its bothers me alot, I get excessive sweat in between my breasts, its dark lining like following my breast line. Ive had it probably since middle school and i’m now 16 and its still there and hasnt improved. I try scrubbing and doing baths but It hasnt really helped. And I also get pimples there like whiteheads but more liquidy and nasty . How can I stop this :(( and does anyone know what this is?