Why does the tattoo blister? How to prevent and treat it? Reason: The sterilization is not strict when tattooing, and the aseptic operation is not enough. The immunity of guests is low. When tattooing, the lip wound is large and the resistance is weak. Bacteria from the external environment take the opportunity to enter, and the infection is mostly herpes simplex, which appears 3-5 days after tattoo. Treatment: timely antiviral treatment, and pay attention to cleaning the wound.