Which statement best describes the earliest skin reaction associated with initial radiation therapy dosing?

• A. Skin irritation and erythema
• B. Open ulcers on the skin
• C. Burned appearance of skin
• D. Sloughing of skin

Answer: (A)

The earliest reaction to initial radiation dosing is an inflammatory response in the skin, showing as irritation with redness (erythema). Radiation damages superficial skin cells and triggers inflammation, causing increased blood flow and capillary permeability in the treated area. This redness typically appears after a week or two of daily fractions, depending on the total dose and skin area.

As treatment continues, the skin may progress to dry desquamation (scaling) and, with higher doses or prolonged exposure, moist desquamation or ulcers. The other descriptions—open ulcers, a burned appearance, or sloughing—reflect later, more severe stages of radiation dermatitis, not the earliest change.