Acne problems

Hi, I am 15 years old and recently had an acne breakout, I did the usual wash more frequently my face, mace masks, etc. It has worked ALOT and in some point it stopped. But there is one place which has been very constant and it is on the chicks... does someone know a common cause for this? It doesn’t look like normal acne it’s like in the inside of the skin but it looks white and there are a lot of them... any advice to make it stop?