Hi,
I have 4-10 pimples on my body at all times. They come up ANYWHERE (except usually not the face).
Some are highly inflamed and painful. Some deeper pimples with a whitehead on top.
I've been to so many derms and tried so many products. (Accutane, BP, Antibiotics, all the likely treatments)
My life consists of watching a movie and itching my back, only to uncover a large pimple that will take days to heal.
I often run to the doctor to get the large painful ones lanced.
This pattern has more or less been with my my whole life.
Diet could also affect how you body reacts maybe you can also take this into consideration as to what food you take.
Have you also tried any natural remedies? It's worth a try though since you're not doing any harm on your skin with organic products. Chemicals might not be working well for you but who knows? The natural ones might be your solution.