long as you're consistent with your carb count it won't matter. I count everything from fiber to sugar alcohol (i.e. 2 grams of sugar alcohol per stick of sugar free gum). I also count each splenda pack I use as one gram of sugar because, while it is "sugar free," it will still add up after multiple packets since in the US, the FDA only requires a food to be less than 5 calories per serving to be considered sugar or calorie free.
Long winded but moral of the story is whether you count them or not, just be consistent.
Also don't overdo the sugar alcohol.. too much will give you a tummy ache