Which of the following ultra-violet radiation cause most skin disorder-: (A) UV-A, (B) UV-B, (C) UV-C, (D) None
Answer is B. Cutaneous responses to uv radiation UVA -315-400nm immediate erythema Immediate pigment darkening- merowsky phenomenon drug induced photosensitivity photoageing UVB- 280-315nm 1000x more erythmogenic, associated with sunburn delayed melanogenogenesis major role in carcinogenesis role in photoageing role in vitamin d synthesis UVB has more damage to skin fitzpatrick textbook of dermatology page 267