Is laser burn on face permanent or temporary? My skin was burnt by IPL laser four months ago. (Photos)

Thank you for your question and posting a picture.  It looks and sounds like you might have Post Inflammatory Hyperpigmentation (PIH).  It may fade on its own over time.  Topical fading creams may also help.  We have been very successful using the PicoSure laser with the FOCUS and / or Flat Lenses eliminating hyperpigmentation with a series of treatments.  FOCUS lens treatments have the extra benefit of reducing fine lines and wrinkles.  This is one of our go to treatments for patients older than 40 and worried about the signs of aging.  This laser is safe for all skin types.  Start with sunscreen every day!  Once you have treated your hyperpigmentation to your satisfaction, you will probably need a follow treatment every 6 to 12 months depending your level of re-pigmentation.  I hope this helps.

It looks as if there is some PIH (post inflammatory hyperpigmentation) post IPL.  This will typically fade over time (but it can take 6-12 months or longer).  The best is to sun protect with SPF of at least 30 (I prefer a physical block with zinc/titanium) and reapply.  Also, it may be good to utilize a retinoic acid at night (such as tretinoin) along with a bleaching agent (hydroquinone).  I recommend Vitamin C serum (skinceuticals C/E/Ferulic) as an antioxidant as well.