At the very least, to fight false allegations of abuse you need compentent legal counsel.
You'll need to do your best to prove that the allegations are unfounded, malicious,
or incapable of having occurred.
Unfounded allegations are allegations where there is no supporting proof and no evidence that
to show that the abuse actually occurred.
Malicious allegation are frequently made in the context of heated divorce and custody
battles. They are suspicious by their very timing and may be obvious to the trained
professional or the informed layman.
Allegations that are incapable of having occurred are those where you can prove you
had no physical access to the child (such as being out of town or in the hospital on the
dates when the abuse is alleged to have occurred), or other factors that would make it
an impossibility for you to have committed the alleged abuse.