3 weeks post op lipo insanely itchy. Why? What can I do to help it?

Some medications may cause itching all over. Check and see if anything you're taking may be causing this. Check for rashes on your skin to see if it is due to a contact dermatitis. Otherwise maybe visit your primary doctor to run some blood tests. 

Itching is fairly common after surgery.  This may be organic in nature. If there is any sign of rash or allergic reaction, that would be something different.  If your plastic surgeon does not think it is lipo related, consult with your PCP to see if benadryl would help.Kenneth Hughes, MD, Board Certified Plastic SurgeonLos Angeles, CA

Thank you for your question. It's not possible to give you specific advice without examining you in person, but itching after liposuction is not uncommon. As the small nerves wake up after a liposuction procedure, they can give the sensation of itching. This is similar to incisions which can itch as the small sensory nerves regrow. Make sure that there is no sign of infection or rash and express your concerns to your surgeon if they occur. Congratulations on your procedure.

Itching can be typical during the healing phase after your procedure. To improve healing, I recommend adding hyperbaric oxygen and lymphatic massage along with your compression to help decrease swelling. To improve your final results, I also recommend adding vanquish for further fat removal, exilis/venus legacy for skin tightening, cellutone/z wave to make the skin smooth, remove scar tissue, and improve the skin’s appearance. Best, Dr. Emer

You're likely getting irritated by sweat that's being trapped on your skin surface by your garment. I suggest you keep the skin dry. Speak with your plastic surgeon about how to keep it dry. Best wishes, Dr. ALDO 

Hi, thanks for the question.After a lipo it is not usual that this condition happens. There is a patient that maybe after trasfucion, it may not be your case, it can happen, patients who wear the belt without a shirt under it may be a condition, in some patients the medicine that was taking a delayed reaction as an allergy , with symptoms of itching. I hope the information will be useful. Thank you.

Thank you for the question and the information provided.
My recommendation is to visit your PS for an in person evaluation to determinate what is causing the itchy. It is very uncomfortable and he / she can perform exams to know the reason or prescribe you medications. 
Best Wishes.