What Might Cause a Skin Rash Following Vaser Liposuction?

Hi, it is hard to assess without photos and without detailed information, such as how far you are with your recovery or when did you first notice the rash. There are a number of factors that can contribute including #medication, #garment or #bruising. 
It is best to discuss with your surgeon other options for compression garment or if you are allowed to put topical medication for the rash. You may also ask if there's a need to change your aftercare medications. Also, if you are in your early days of recovery, redness is usually the beginning of a bruise and will progress to blue, purple, and finally to healing stage of green and yellow.
Follow the instructions provided by your plastic surgeon when moving forward through the healing process and make sure you get plenty of rest and treat the incisions well. I hope your concern was addressed. 
#RealSelf100

Skin rashes are often due to the garment or topical medication.  Many topicals contain sulfa and this causes rashes for many people.

Without pictures and a more detailed description of your rash  your question is difficult to answer. However, post surgical rash can be caused by a number of factors 1) drug reaction: intraoperative antibiotics, anesthetics, pain medications, post op antibiotics etc 2) contact dermatitis from compression garments, steristrips etc.  So, please call your plastic surgeon and describe the rash if you  are having breathing issues, go to the emergency room. Best of luck Dr. Renucci

If the discoloration is not just limited to the area treated by VASER, then it may be a systemic reaction to a medication; however, if it is limited then it is likely due to the heat generated by the VASER probe especially if it was left on high continuous setting for a long duration too close under the skin. If you have a sensitive skin or history of dermatographism, your skin will likely react to any trauma. You may also have had a localized reaction to the content of the anesthetic solution used in wet or tumescent liposuction techniques common with VASER liposelection. You will need to stay in touch with your surgeon and possibly start on anti-inflammatory medications or topical hydroquinone to help fade the discoloration.