Pigment-specific lasers (pulse-dye pigment, Q-switched alexandrite CO2, Q-switched ruby, and Q-switched Nd-Yag) are generally recommended only for recalcitrant melasma following the failure of all other therapies. On the other hand, these lasers are the treatment of choice for isolated pigmented lesions, such as lentigos (49).
Q-switched ruby lasers have been successfully used treating specific pigmented lesions such as benign melanosis, labial melanotic macules, mucocutaneous melanosis associated with Peutz-Jeghers syndrome, and phacomatosis pigmentovascularis. Efforts to treat melasma and solar lentigines with the Q-switched ruby laser have not been successful (50-54).