Which term describes blisters that are formed on the skin?

The term that describes blisters formed on the skin is vesicles. Vesicles are small, fluid-filled sacs that can develop on the skin as a result of various conditions, including infections or allergic reactions. They are typically less than 0.5 centimeters in diameter and can appear clear or contain a yellowish fluid.

In contrast, papules refer to small, raised bumps on the skin that are often solid and do not contain fluid. Wheals are raised, itchy areas that can appear as hives, typically resulting from an allergic reaction, and are more transient in nature. Tumors, on the other hand, are larger masses of tissues that can either be benign or malignant and are not specifically characterized by their fluid content. Therefore, the definition and characteristics of vesicles make it the correct choice for describing blisters.