Whilst it doesn’t cause them, if you have ever had a cold sore before, or been exposed to the herpes virus (even if you have not experienced cold sores since you were a child) then lip tattoo can cause an outbreak of cold sore blisters/reactivate it – as can any type of lip trauma like sun/wind burn. As such, it is important to obtain anti-viral cold prescription medication prior to having this procedure (and any lip tattoo retouches) done, to prevent an outbreak occurring.