i think you have skin infection
caused by bacteria, hence
you should maintain proper hygeine in the areas were you sweat a lot.
I whould suggest you to consult a qualified homeopathic doctor
in your area and take internal medicine,avoid any external application as it can cause suppression and delay in complete recovary. Homeopathic medicine like Hepar sulph, sulphur, silica will help in this condition and will prevent reoccurence.