What is the medical term for an elevation of the skin filled with serous fluid?

The term "blister" refers to an elevation of the skin that is filled with serous fluid, which is the clear, yellowish fluid that can accumulate between the layers of the skin in response to irritation, injury, or burns. Blisters are typically characterized by their fluid-filled structure, which often forms as a protective mechanism for the underlying tissue. This elevation occurs as a result of the separation of the epidermis from the dermis, allowing fluid to collect in the space between them.

Cysts, while also elevated lesions, are typically filled with keratin, pus, or other materials depending on their type, and are not specifically characterized by being filled with serous fluid. Keloid scars are abnormal overgrowths of scar tissue that often appear elevated but differ significantly in composition and formation. Striae, commonly known as stretch marks, are linear scars that form when the skin is stretched rapidly and do not involve the accumulation of fluid. Thus, "blister" is the most accurate term to describe the elevation of skin filled with serous fluid.