Q-Switched Laser

The Q-switched laser is used for pigment problems with a clear diagnosis. Commonly discussed indications include epidermal lesions such as freckles and solar lentigines (sun spots or age spots), dermal lesions such as nevus of Ota and Hori's nevus (acquired bilateral nevus-of-Ota-like macules), and the removal of tattoos and old cosmetic eyebrow pigment. These lesions sit at different depths and behave differently, so the first step is always a medical assessment of what the spot actually is.

It targets pigment particles, not skin texture or structure—pores, acne scars, and laxity are outside its scope. Raised melanocytic moles are generally not treated this way either; they usually call for clinical evaluation and, when removal is warranted, excision with pathology to rule out malignancy. Melasma is a special case that can rebound or darken with aggressive treatment, so whether and how to use a laser for it should be an individualized medical decision.