Skin/Nails and Chemotherapy Chemotherapy can affect both the skin and nails. It may cause an increased sensitivity to the sun as well as redness, rashes, itching, peeling, dryness, or acne. Nails may become darkened, yellow, brittle, or cracked, and may also develop vertical lines or ridges. Hair Loss and Chemotherapy People often choose to wear wigs, scarves, or hats while or after losing their hair. If this is what you would like to do, pick them out ahead of time and start wearing them before your hair is completely gone. Hair Loss--One Woman's Story With chemotherapy, hair loss usually begins within two to three weeks after the start of treatment, and may continue over the next month. In some cases, total hair loss occurs in 24 hours.