I'm gonna go ahead and say I'm sorry for my temerity.
Anyways, Madman, the portrait is quite nice and it's obvious you've got your share of experience in working with color, so, keep it up and I look forward to seeing more from you

.
That being said, I think you've got a lot of pixels placed at random on the face, making it look like it has, as Helm said, a skin condition
Though I don't think it can be said there's an actual problem with that, I made an edit with cleaner skin:

I also, more logically, changed the anti-aliasing on the hair, cut out parts of the shirt, and made the light cover a larger part of the face.
I'll start by explainging the lighting change:
In yours, the mirroring in the face makes it look like both sides are equally lit, and that combined with the shadows on the forehead make it look pillowshaded (Having the light between the viewer and the object, in case you didn't know), while your nose is shaded like the light is up and to our left of the subject.
So to get rid of the pillowshading I expanded the light to further follow the lightsource effecting the nose.
The shirt:
It was confusing to me why it would go up like that (Actually, was it hair?), so I removed it. If it is your hair, I think you need to find a way to separate it from the actual shirt.
The anti-aliasing:

You're just creating a blur effect with this. There's never an actual change in the object-dark-light-background formula, and this actually serves to make jaggedness more obvious, which is the opposite of what AA is supposed to accomplish.

This is what I changed in my edit. Instead of using 2 pixel blurring like you are, there's simply a 1 pixel line of AA surrounding the curve, with a few exceptions. First,
the purpose of anti-aliasing things is to make it look smoother then you could with whole pixels, so effectively anti-aliasing is using pixels to make it look like there's less then a pixel there, but, you know, more then nothing.
So, let's look at the curve. The point marked H is the highpoint. Well, the 2 brown pixels are. They're the part that looks like it goes out the furthest from from the object. Effectively, they can be viewed as, say, 8/10 of a pixel.
The orange pixels, are about, uh, 4 or 5/10 of a pixel,
Next to that, at point T, there's the light yellowish orange which would be about 1/10.
When you look at it as there estimated pixel ratio thingamabobbers, it goes:
1/10 4/10 8/10 8/10 4/10
Since the 8/10s are the biggest looking, they stick out the farthest.
T is actually there to mark where the AA is effecting a different line, since next to the 1/10 is one of those 8/10, so, uh, yeah.
I have a feeling some of my meaning was lost in that long-ass post.
