An abusive ad hominem fallacy occurs when the ad hominem fallacy is committed by means of direct personal insults.

Here is an example:

In a political debate, one candidate says to another:

"You were raised in a barn, and you have poor fashion taste. Therefore, anything you say about the new tax initiative is worthless."

The problem is that the target's opinion on the new tax initiative is not really being addressed, let alone falsified, by the character attack.