Vitiligo is usually associated with thyroid issues, so it may be an idea to check that out as well.
At the moment, Vitiligo is untreatable.
There are a number of websites & forums around to lend an ear, discuss individual circumstances etc.
These would be a good starter for you to clue up on the disease (I hate that word).
Protopic is unavailable in the UK, the doc's here do not provide anything to deal with it, not that there's anything out there which makes a difference anyway.
Try to keep your boy covered up when it's sunbathing weather, get him plastered in high factor sunblock.
If he does get a bit of a tan, then the vit is more noticeable.
In the winter, the tan fades, and the affected patches will blend into the surrounding areas, and no-one would ever know he has it.
I've just noticed that I'm whittering on here without knowing (or really caring) what colour your skin is.
The fact is that pale skinned individuals can get away covering up better than darker skinned people.
If it is really noticeable, then you can apply a bit of makeup to blend in the patches.
It's maybe a tad tough to say, and pretty hard to understand at the mo', but your lad should start treating it as a joke, or making light of it when someone asks him about it.
There are a lot of people who will stare, it's best if he can deal with them upfront rather than let it get him down.
The current Mrs r0m has it.
She is in a customer facing role, and loves winding people up about it.
She's told people that it's highly contagious, that she's going for the Jersey cow look, her fake tan went horribly wrong etc. She also feigns shock when someone points it out to her.
Generally speaking...people are stupid & insensitive.
Your lad will really need to learn to deal with it in his own way, I personally think the way the Mrs deals with it is a whole lot healthier than getting upset every time someone says something.
I'm sure you, your wife and the wee fella will come to terms with it soon enough, please don't fork out any more money to some quack who is unable to provide a solution, or any help whatsoever.
As for the makeup route, you're maybe best telling him that it's to blend the edges to make it less noticeable, do NOT use the word "makeup"
Anyway m8, I hope you can all come to terms with it and accept the situation soon.
My PM's are on if you want a natter.
Cheers.