Amazing what the sun can do to your skin it's prematurely aged him like 20 years
Not only that, but everything he does/doesn't compounded together:
*He never drinks water and has severe chronic dehydration. That's probably the second biggest contributor
*He eats like shit. Mostly cheap carbs or sugar since it's what's readily available.
*He's constantly exposed to the elements. Strong winds, especially hot/cold and dry are hell on your skin.
*He's constantly exposed to the sun. But not just any sun, the Colorado sun which has the added danger of much higher UV indexes because of the elevation. They have the highest per capita diagnosis of skin cancer in America.
*He refuses to bathe. Cooking in your own filth is a good way to deteriorate.
*He's had chronic ailments because of said lack of hygiene. Scabies, trench foot, lesions, etc.
I'm surprised he hasn't done more damage by hitting himself. I'd at least expect an even wonkier nose, more missing teeth, some cauliflower ear or some misalignment of the eyes from breaking his eye socket before but it seems that it hasn't caught up to him yet.