I always worry about ventilation with cases, though that may unwarranted depending on the particular case / skin. I was cheap (and not sure if the laptop was my root issue at the time), so I ended up putting duct tape over the area my wrists touched, and that helped a lot. It looked pretty silly though.

That said, when I had the option to get a laptop where I wouldn't have to think about it at all (plastic cased thinkpad), I jumped for it. Maybe I've just developed a deep-seated, emotional resentment for metal bodied laptops in general after spending so long dealing with itchy/oozy hands, wrists and forearms. Also all the doctors who just prescribed steroid creams and blamed stress...

Yeah, I get it. I think plastic cases are going to be a tough sell for a company looking to be environmentally friendly. :)

You're also not in the majority, but as I stated, I'd prefer a non-metal looking laptop. I've got a Razer Blade Stealth 13 which I had to put a skin on because it's a fingerprint magnet. Skins really aren't that bad, and they're designed to not block the vents.

Unless you just want to put a skin on your laptop, this feels like the whole "Rubber Band Antenna-gate" thing from Apple years back. The device should work as-is without some extra covering being required.

Not everyone has skin allergies, but if you are mass producing devices that will be in close contact with skin for long durations, made with metals that are well known to cause skin irritation - sooner or later you're going to run into people that are affected.

Additionally, due to the way that the allergic sensitization process happens - many people only develop a reaction after frequent, long-term exposure. So it's very possible to use a metal laptop without experiencing an issue for a long period of time, and then to develop problems down the road. This, along with the allergens sometimes being from contaminants in the metals (so not listed and somewhat variable) - makes it very hard to predict and to identify afterward.

So while I'm "rare", in that I know I've got an allergy with a very noticeable reaction that can be triggered by laptops - many people don't know that they are at risk of developing it, even though they are. Or maybe they know they have a nickel sensitivity (this issue is very common with people who wear cheap jewelry) - but they don't know a laptop can trigger it.

Unless there's a big push to do some sort of widespread contaminant testing on laptops, I imagine this issue will grow if metal-body laptops continue to be the norm.