Ultherapy delivers energy via ultrasound through different depth transducers. The most shallow transducer is designed to help the more superficial skin layers. There is, not uncommonly, some linear welting, or swelling from the 1.5mm transducer, but this lasts usually a few hours. Some patients are sensitive to physical rubbing, pressure, stroking (dermatographism) and get hives when they scratch themselves with their fingernails. These patients are expected to have longer lasting welts from the 1.5 mm. Ultherapy is safe if the provider uses adequate ultrasound gel and the correct pressure. Safety can be improved by paying attention to these two variables and the physician is able to look at the monitor throughout the whole treatment to ensure that the applicator is placed well.Usually the swelling goes away on its own without any bad results. At this time, as it's been several days, you should be asking the question to the physician who treated you and you should be seen in person for an evaluation, and not asking physicians for opinions who can't see you in person, nor know the technique used in treating you. Contact your physician.The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice. The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs. If you are experiencing a medical emergency proceed to your nearest emergency room.