What does alopecia refer to in the context of chemotherapy?

Alopecia refers to hair loss, which is a common side effect of chemotherapy. Chemotherapy drugs target rapidly dividing cells, and since hair follicles are among the fastest-growing cells in the body, they are often affected by these treatments. This leads to a reduction in hair growth or complete hair loss in areas such as the scalp, eyebrows, and other body hair.

The other options listed do not accurately define alopecia. For instance, swelling of the scalp could be related to inflammation or other conditions but is not the medical term for hair loss. Severe dryness of the skin and changes in skin color relate to other potential side effects of chemotherapy, such as skin reactions or sensitivity, but again, do not describe alopecia itself. Therefore, the most appropriate definition in the context of chemotherapy and its side effects is indeed hair loss.