Does Thorns damage trigger Area Damage?
Will Thorns damage trigger the Area Damage effect?
If an enemy hits me and takes Thorns damage, does it have a chance to trigger the Area Damage on the creature that took the Thorns damage?
Solution 1:
According to the extensive testing and research done for this article, it states that:
AD cannot be procced from thorns damage.
This article was also advertised on the official Diablo 3 website.
Solution 2:
While I can't give you a definitive answer, from research and the internet it would appear that it does not. Look at this post on the D3 forums. To sum up: You can't proc from a proc.