Does Accutane effect existing tattoos?

Thanks for your question.  It is an interesting idea.  Tattoos fading while on accutane is not a commonly seen problem, but I suppose if the skin is excessively dry and peeling, it could cause some irritation in the skin where a tattoo is, and it might lose some ink. I am just speculating, however, and have not seen this phenomenon in real practice.  I would definitely try and moisturize the skin over the tattoo as well as you can, and keep it covered in the sun.  Best of luck!