Which branch of medicine studies the skin, its functions, and diseases?

Dermatology is the branch of medicine that specifically focuses on the study of the skin, its functions, and diseases. This includes a wide range of conditions that affect the skin, hair, and nails, such as acne, eczema, psoriasis, and skin cancer, among others. Dermatologists are trained to diagnose and treat these conditions, making their expertise essential in understanding not just the structure of the skin, but also its role in overall health, and how it interacts with other systems in the body.

The other branches mentioned, while crucial in their respective fields, do not concentrate on skin-related issues. Oncology deals with cancer and its treatment, cardiology focuses on heart conditions, and pediatrics centers on the health of children. Each of these specialties has its unique focus, but when it comes to the skin specifically, dermatology is the definitive field of study.