There are two types of skin rash in DCS: cutis marmorata, which is associated with PFO, and Type I skin rash (itchy and blotchy like hives), which is not. Going by the photo and your description, this could be the latter. As to cause, this is just speculation, but if you've been affected multiple times by (presumably) PFO-related cutis, you may be one of those divers who tends to bubble more than average. The pictured area is right where you'd see the most friction and pressure when boosting yourself back into a RHIB. It's possible that this was enough to liberate dissolved gas in the area.Skin bends are interesting and causes..I was diagnosed with pfo several years ago following an incident. Various discussions I limited my diving per day to two and depth max 20m with long surface intervals with no problems.
A recent trip though I had a skin rash after climbing onto a rib after a controlled dive.
No where near deco and just 18m for 52 minutes.
But, it was an effort in current getting onto the rib and stupidity occurring by thinking I could climb on with my gear.
Two hours later I started itching and then a rash appeared on the area of my abdomen chest.
It subsided after a few hours on its own but my thinking being that carrying a bit of extra fat may have caused me an issue as redness was only around my added fat areas,
My thinking and advice given that after a dive certainly rest straight away as this is the ‘ danger Zone ‘ and certainly no hot showers.
My plan now it too lose more weight as I still
carry a gut and boobs and stick to my planned diving to avoid future issues.
Best regards,
DDM