Do tattoos impact pulse oximeter accuracy?

Anecdotal observations have suggested potential oximeter inaccuracy when readings are obtained through tattoos or henna. Many manufacturers warn this can be a cause of inaccuracy. Controlled studies are lacking to characterize this effect, and performance may vary by oximeter.  

References: Zolfaghari et al, Emerg Med J 2015; Battito, Anesth Analg 1989 

Keywords: ink, tattoo, henna, fingerprint