[mriver8 (OP)]

Not dry skin but pale, slightly droopy, not overly dry but no sweat, and discolored like someone who died a few minutes ago?

[alancalverd]

The only known cause of parazombism is being undead, recently deceased, or soon to be late.

[evan_au]

What can cause human skin to look like a zombie's skin?

I don't know of anyone who has seen a zombie, so I don't know of anyone who could answer this question (or ask it, for that matter).

If your skin is pale, you could try getting some sun. This might be difficult towards the end of winter if you live in a cold climate - but take it slowly at first.

[exothermic]

Necrotizing fasciitis: http://www.liveleak.com/view?i=327_1354256072

[mriver8 (OP)]

The only known cause of parazombism is being undead, recently deceased, or soon to be late.

Like a meth addict's skin where the blood vessels are dead on the top layers.

[RD]

Like a meth addict's skin where the blood vessels are dead on the top layers.

The vasculopathy (and consequent ischemia => necrosis ) is not limited to their skin : "meth" causes systemic vascular disease.
Self-inflicted injuries due to formication would be limited to "top layers" of skin.

Generally anaemia would be a more common cause of people looking ghostly-pale, rather than drug abuse ... http://www.who.int/vmnis/anaemia/prevalence/summary/anaemia_data_status_t2/en/

[mriver8 (OP)]

Like a meth addict's skin where the blood vessels are dead on the top layers.

The vasculopathy (and consequent ischemia => necrosis ) is not limited to their skin : "meth" causes systemic vascular disease.
Self-inflicted injuries due to formication would be limited to "top layers" of skin.

Generally anaemia would be a more common cause of people looking ghostly-pale, rather than drug abuse ... http://www.who.int/vmnis/anaemia/prevalence/summary/anaemia_data_status_t2/en/

Specifically what chemicals in gas, water, or dust can cause this? Any water additives/contaminants found in supplies? What about acoustic energy?

[Space Flow]

It takes a combination of factors to convincingly make skin look like a zombie's. 

In order of priority, here are the main requirements.
1. You have to start with a good make up artist.  (I could recommend a couple) 
2. You have to back that up with the appropriate lighting. So a good DOP (Director of photography) is essential. 
3. Add to that a really good camera operator, because the camera angles can play a big part in the look. 

These people above are the main ingredients, and if you get those right, you are 95% there. 

[exothermic]

It takes a combination of factors to convincingly make skin look like a zombie's. 

In order of priority, here are the main requirements.
1. You have to start with a good make up artist.  (I could recommend a couple) 
2. You have to back that up with the appropriate lighting. So a good DOP (Director of photography) is essential. 
3. Add to that a really good camera operator, because the camera angles can play a big part in the look. 

These people above are the main ingredients, and if you get those right, you are 95% there.

I take it you didn't click the link in the 4th post.....