Can you become a dematoligist if get your GED instead of high school diploma?

It is unlikely that you can become a dermatologist with a GED instead of a high school diploma. Most medical schools require applicants to have a bachelor's degree from an accredited college or university, and many also require applicants to have taken specific science and math courses during their undergraduate studies. A GED may not provide the necessary academic foundation for medical school, and it is unlikely that you would be able to gain admission to a medical school with a GED alone.