Hello
Hello and welcome to ChatDoctorcould you please clarify how large the lesions are and where precisely they are located i.e. upper back or lower. You mentioned living in a humid climate, do you sweat a lot? Do you have oily skin? Does anyone else in your immediate surroundings have these lesions. I would advise you to have a basic blood test done and visit a dermatologist this condition you are having might be a simple fungal infection(Tina tricolor). Allergies to Chat Doctor. Good luck