Vitiligo is an autoimmune skin condition where the immune system has mounted a production of proteins (antibodies) that attack pigment-producing cells (melanocytes) along top layer of the skin. Within a vitiligo skin patch, there is a complete depigmentation, perhaps with islands of repigmentation. This condition may run in some family and can be associated with other autoimmune conditions such as thyroid disorder, diabetes, anemia, etc. The best treatment available involves combination of NBUVB (narrow-band ultra-violet B) phototherapy and topical tacrolimus ointment.
Unfortunately, vitiligo can occur in places where the skin may be traumatized, e.g. abrasion on knees. Therefore, there is theoretical risk wherever a laser is performed. Individuals with history of vitiligo should consult with a board-certified dermatologist, weigh risks and benefits before making an informed decision about laser treatments.