Ds making himself sick

[Magneto]

Ds is 21 months and has a history of finger chewing when teething, recently he has started shoving his fingers further back in his mouth (must be back teeth coming through) and it keeps making him gag and 4 times in the last 3 days he has even made himself sick by doing this.

Removing his hands from his mouth just results in a screaming tantrum from him and he has been spending increasing amounts of time with his dummy in because it stops the finger chewing.

Does anyone have any tips on how to stop this, or is it just a case of distract distract distract?

You're right about distraction.

Anything else would just call attention to the behaviour and you could end up with him doing it for control. I'd just let him have the dummy whenever he wants it and worry about cutting that down at a later date.