Ahh yes, but alcohol is not a narcotic. The medical category of "narcotic" includes opiates, such as herion, morphine, and synthetics like oxycontin and methadone.
I think the point may be ESRB has no idea what Skooma actually is.
I can't recall skooma pipes in Oblivion? Even if they were in Skyrim maybe the ESRB did not put 2/2 together?