Kratom does contain opioids and I think even an outright opiate. Too lazy to look it up now.
I don't have much experence with opiates but Tramadol sure had me rubbing my face.
Wonderful drug as long as you don't get addicted. Antidepressant, mild stimulant. Great for work or workouts. I just noticed I'm rubbing my face now a little. 
Kratom and Tramadol absolutely will give you the opiate itch.
Hanky is retarded.
I was taking 100-200mg of Tramadol a day for about 4 months due to serious knee pain.
Almost itched my nose off my face a few times.

I feel it on Kratom if a take a few doses throughout the day.
A few weeks ago i went camping and took a few grams 3 times throughout the day, by the second dose i could feel the itch. It also makes me fidget with stuff a lot, almost like i'm hyperactive. My GF has commented on it.