Which radiation produces an erythema within 6-8 hours?

• A. Minimal erythema
• B. Infrared radiation
• C. Ultraviolet radiation
• D. Second-degree erythema

Answer: (A)

Erythema that appears about 6–8 hours after exposure is the classic acute reddening produced by UV light. The term minimal erythema describes the smallest UV dose that yields visible reddening within that 6–8 hour window, so it directly matches the timing asked in the question. Infrared radiation mainly causes heat and does not produce this UV-type sunburn reddening in that early timeframe. A second-degree erythema would indicate a much deeper burn, not the mild reddening described by the minimal erythema concept. Ultraviolet radiation is the overall cause of this kind of erythema, but the label that specifies the mild, onset reddening within the 6–8 hour window is minimal erythema.