What can cause rashes under the armpit, back, and chest with no other symptoms?

Hello doctor,

I am a 39-year-old male. I noticed a couple of small rashes present under my armpit. Before three weeks, I had a rash on my chest and back. It was not itchy. It started to spread slowly in my chest and back. I have a few rashes on my upper arms. I have some different types of pimples on my buttocks and a few on my knees. I have tried using Hydrocortisone 1 % cream for two weeks. But there is no relief. I was taking Testosterone Enanthate 100 mg for a week, DHEA 25 mg, and Arimidex 1 mg for six months. But there was no relief. I changed the dose to 50 mg of DHEA, Arimidex 1 mg, and Testosterone Enanthate. I took a single dose of Testosterone Cypionate along with it. After a week, I did an HCG test. So, I stopped these medicines. My rashes are not gone. I do not have any hair loss, headaches, mouth issues, and pain. I do not have any past medical history. Please suggest.