I have an area of hypopigmentation on my chin as a result of an IPL treatment from a board certified plastic surgeon? (photo)

Hi Susan.  You are correct, this does look like hypopigmentation.  Have you reviewed the concern with your practitioner and if so, what does he/she suggest?  
If your practitioner is not prepared to move forward with any remedial treatment, we would suggest considering fractional laser resurfacing.  While there is no treatment that is assured to bring back color to a hypopigmented area, fractional resurfacing can help generate new collagen and in the process can help improve the color difference.  
The longer the scar heals without treatment, the more difficult it will be to change the color.  To see some examples of scar treatments with Profractional resurfacing, click on the link below.  

A combination approach will give the most improvement. I recommend lasers, microneedling/prp, and radiofrequency treatments. I recommend getting a formal evaluation with a cosmetic dermatologist. Best, Dr. Emer

Thank you for your question susanmnilon. I am sorry to hear about your situation.
IPL is a great treatment for facial rejuvenation. For my patients I treat hypopigmentation secondary to laser treatments with fractional laser treatments. It has been reported that applying Latisse immediately after the fractional laser can help re-pigment areas of depigmentation. It may work for hypopigmentation. Please consult with a doctor for specific recommendations. Good luck!