What are your opinion on fillers/Botox with melasma patients?

Botox or filler injections should not impact or affect melasma, so you should have no problems if you'd like to have your frown lines treated. Melasma is typically influenced by a variety of other factors including sun exposure, hormonal changes (i.e. through pregnancy or oral contraceptive use), and genetics or family history.

Neither botox or fillers will have any effect on worsening melasma. Rarely , fillers could cause an inflammatory response called post inflammatory hyper pigmentation at the site of injection  .This is a reversible phenomenon that can be treated with bleaching agents such as hydroquinone  and does not cause the melasma to worsen.