Is Laser Treatment Effective For Hyperpigmentation?

Hi doctor, my mother is 52 years old. she was diagnosed 2 years age as photosensitive lichen planus she received many medications as: corticosteroids,lightening products, oral antihistamines, sun blockers and lastly doctor advised her for laser therapy as a curative for her hyper-pigmentations. I want to know if laser will be effective to treat or not and if it will cause any side effects