Which symptom is most commonly associated with acute UV exposure on the skin?

• A. Erythema
• B. Hyperhidrosis
• C. Rash from allergic contact
• D. Blistering due to infection

Answer: (A)

Exposure to UV light causes an inflammatory reaction in the skin that most commonly presents as erythema—the red, sunburned appearance from increased blood flow in the superficial vessels. UVB damage to epidermal cells triggers inflammatory mediators, leading to vasodilation and redness within a few hours after exposure. This redness is the best indicator of acute UV injury and is usually the first symptom you notice.

Hyperhidrosis involves excessive sweating and isn’t a direct result of UV exposure. An allergic contact rash arises from an immune reaction to a substance on the skin, not from UV radiation. Blistering due to infection isn’t the typical mechanism of acute UV damage; while severe sunburn can blister, that mechanism is due to tissue injury rather than infection.