IPL on face. Now dark and blistering on my chin. What should I do? Will it leave a scar? (Photo)

I recommend following up with your cosmetic dermatologist for after care. I recommend Silagen + Bioshield and PDT therapy to promote healing. I always combine IPL with microneedling/prp to improve outcomes. See an expert. Best, Dr. Emer

Getting a burn or blister is a potential side effect of IPL but I would not describe this as normal.  When we have a potential side effect like this, we recommend using Aquaphor on the area and eliminating all sun exposure to the area.  It's very important to not let the area dry out.  The growth factors in PRP may help but its more important to keep the area covered with Aquaphor.  I also recommend evaluation by a dermatologist.  

This is not a normal response to IPL treatment.   This looks consistent with a second degree burn.  I would recommend silvadene cream or biafene to the area until healed. You will also need daily sunscreen use. There is a chance of some post inflammatory hyperpigmentation which hopefully will resolve with time. 

From your photos, it appears you may be having a secondary infection to the areas on the chin that blistered. You should see your physician to determine if you do, and if so, they can treat this. Some types of infections, like impetigo, may be treated with topical medications, but you should be seen by your physician for this. I would not recommend any further treatments of any kind until the infection is seen and evaluated by a physician.Best wishes,