<prompt> This rash appeared 9 hours after a scuba dive. What is the diagnosis?Decompression sicknessJellyfish envenomationMycobacterium marinum infectionPhylum Porifera contact dermatitis  <response>: Answer A. Decompression sicknessCutis marmorata is a dermal manifestation of decompression sickness. Initially, there is erythema accompanied by pruritus, and then the rash spreads irregularly and deepens in color. It develops a mottled appearance, with areas of pallor surrounded by cyanotic patches. During recompression, the rash resolves. 