When is the right time for Fluorouracil and Kenalog to be injected in a scar that is healing? (photos)

Hello, i would recommend the Kenalog, each 21 days. Now seems a good time to start. Also any silicone based gel applying some pressure while massaging your scar would work. Best regards

Thank you for your photographs and questions.  Scars can often remodel for a year or more after surgery as they thin, become flatter, and fade in color.  It does appear, however, that some of your scars, predominately of the lower abdomen and belly button are displaying hypertrophic scarring. I would recommend the steroid injections into the thicker scars, while also trying silicone sheeting to gain some improvement in appearance.  

I do agree your scars appear hypertrophic.  I would recommend steroid injections at this point in time.  2-3 injections should help them flatten out and soften. 

You are presently in the stage of wound healing called remodeling. If you will just leave the scar alone there are 99 chances in a hundred that it will heal very satisfactorily.

Your Plastic Surgeon knows your medical history and operated on you.  I would talk with him regarding benefits of intralesional steroids and in his experience when would be an appropriate time to start.  Intralesional steroids do help flatten scars.   They are injected with a needle and usually require several treatments.  This can be painful and has associated side effects.  They can thin the skin, can cause hypopigmentation and there is a small risk of infection or would healing breakdown.  Most doctors recommend a trial of Silicone gel sheets or liquids first.  They can help flatten raised scars.  They are relatively inexpensive and can be purchased at a local pharmacy.  They have minimal side effects.  I usually recommend a trail for up to 12-16 weeks.