Lifetime skin rashes. Just want to try!

My sisters and I,have a reoccuring rashes on our face.We have to use some type of ointments to make it disappear and it works and the side effect makes our skin thinner.We have to put an ointment in our face EVERY SINGLE NIGHT since we're just kids.We don't have a choice,because our rashes will just come back again.I tried not putting an ointment before and it makes my face red, dry and super itchy and I feel really uncomfortable.The cause of our rashes is because of the heat.My youngest sister is even worse because the rashes that we're having in the face, she's also having it in her private area down there,but it is just outside and she's only 8,what more if she already have her period.She also uses the ointment ever since the day she's born and that makes her skin thin too, we don't have a choice.The doctors that we went to offers different soap and ointments but it doesn't work. My mom thinks that the problem is in our blood. We know that this is for lifetime but I just want to try