This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Medicine
This rash appeared 9 hours after a scuba dive. What is the diagnosis? 
Select and explain. 
A. Decompression sickness, B. Jellyfish envenomation, C. Mycobacterium marinum infection, D. Phylum Porifera contact dermatitis
A: Decompression sickness
Answer: A: Decompression sickness 
Explanation: 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.