A client with exfoliative psoriasis is being treated with ultraviolet radiation therapy three times a week. Which finding indicates overexposure? A. Lightening of the skin B. Crusting of lesions C. Appearance of blisters D. Desquamation

Let's look at each option and discuss whether it could be an indication of overexposure to ultraviolet radiation therapy. A. Lightening of the skin: This could be a normal response to ultraviolet radiation therapy as it can sometimes cause the skin to lighten. However, it does not necessarily indicate overexposure. B. Crusting of lesions: Crusting of lesions could be a sign of the healing process, as the skin forms a crust to protect the delicate new skin forming underneath. This doesn't necessarily indicate overexposure. C. Appearance of blisters: Blisters can be a sign of overexposure to ultraviolet radiation therapy, as the skin may become damaged from too much radiation. This option is a possible indication of overexposure. D. Desquamation: Desquamation refers to the shedding of the outer layers of the skin. It is a natural process that occurs as new skin cells replace old ones. It is not an indication of overexposure to ultraviolet radiation therapy.

Based on the analysis performed in Step 1, Option C (Appearance of blisters) is the most likely indication of overexposure to ultraviolet radiation therapy. This is because blisters are a sign of skin damage and can be caused by too much radiation exposure. Thus, the correct answer is C. Appearance of blisters.