Not exactly a natural products question, although naturally-occurring dyes have been used for millennia for body decoration.
My elder SiBling, Prof Tara Smith at Aetiology, wrote a post last week on a Morbidity and Mortality Weekly Report article about cases of community-acquired methicillin-resistant Staphlococcus aureus infection in clients of tattoo “establishments” with poor regard for sterile technique. (BTW, “aureus” refers to the golden color of the bacterial colonies that form when cultured on solid media.).
A quick glance past the purulent picture reveals such gems as “guitar-string needles,” “computer ink-jet printer cartridge,” and “park bench.” Interesting also that the pustules were peripheral to the ink itself, perhaps indicative of lymphatic drainage of the tattoo site.
Tara’s comment thread was abuzz when she revealed herself as having not one, but two, tattoos. Speculation continues to abound as to the physical sites of her body ink, owing to her own statement, “They’re not in oft-seen areas under normal attire, but neither are they anywhere “naughty.”
This led me, of course, to wonder how exactly do tattoos work. Like anyone who watches CSI knows, the epidermis is constantly sloughing off dead skin cells as new skin rises to replaces it. This is why Coomassie Blue protein stain colors your fingers for a couple of days, until those skin cells fall off.
Being tattoo-naive, I was aware that needles are involved in the process, but I hadn’t truly appreciated that the dermis underlying the epidermis is relatively static. According to ‘Go Ask Alice’ at Columbia University’s Health Education Program:
The human skin is made up of two principal parts: the epidermis and the dermis. The outer, thinner epidermis consists of four or five cell layers. The inner dermis is made up of two portions: the upper, papillary region and the reticular region. Tattoos are made by inserting ink into the deepest layers (the dermis portion) of the skin, which shed cells at a slower rate than layers closer to the surface. That is why tattoos can last a lifetime.
(The site producer claims that the ‘Go Ask Alice’ moniker came to him/her in a dream rather than being an obvious reference to the Jefferson Airplane song, “White Rabbit.” – fat chance given the frequency with which the song has been played on New York radio stations for decades.)
But that leads me to another question…what kind of people routinely read a CDC publication entitled, “Morbidity and Mortality Weekly Report?”