I have upper lip darkening after laser hair removal 1 month ago, how long would it take for it to go away?

I already have melasma on my cheeks. I developed darkening on upper lip in the same pattern as laser was applied. It doesn't look melasma but tanned skin. I had dermamelan treatment but no effect on upper lip. is this going to be permanent or would fade with treatment creams in few months time? please comment as i am very nervous it gives my face strange look actually.