I won't go into the entirety of my research into the topic, because it's a lot. But I did my internship studying this question and would like to know what you guys think.
In short, the placement of Otzi's tattoos are within millimeters (most likely due to skin drift) of Chinese acupuncture points. Over 70% of his tattoos follow classical Chinese acupuncture points. These points have been used to treat rheumatism, which Ötzi suffered through during his life time, as well as gastro-intestinal problems.). If you look at them, they also resemble what we see in therapeutic tattooing.
The craziest thing to me though, is that Otzi lived 5200 years ago, and the first mention of acupuncture in China was the Yellow Emperor's Classic of Internal Medicine, in 2600 BC (More likely 300-100BC). However, even at the earliest, Otzi lived between 3350 and 3105 BC, placing his therapeutic tattooing long before China's own acupuncture.
I've seen mention of therapeutic tattooing being done as far back as 6000BC, but I'm not certain on that. So the question is, where did acupuncture really begin? Who discovered those acupuncture points?
Any experts on this?
A followup to the question: Since Otzi was found in the Italian Alps, what (if anything) do we know about either direct (person to person) or indirect (oral history/anecdotal) contact between China/Europe during his lifetime? We're still talking several thousand years before Rome-China or Greek-China contact is presumed. Is there a theory on how the knowledge of acupuncture might have gotten from Otzi to China if the OPs question/supposition is correct?
And btw - great question. I'm hoping we have some experts reading today!