White Spots After Laser Treatment: Understanding Post-laser Leukoderma

By Dr. Charlene CY Ng ｜Department of Dermatology and Aesthetic Medicine Center, Chang Gung Memorial Hospital

"Laser treatment may initially lighten dark patches. However, some people later develop small white spots or a mottled appearance. These changes warrant reassessment before proceeding with further treatment."

A patient’s experience

A woman in her forties had undergone picosecond laser treatments monthly for nearly three years to address facial pigmentation. Although she initially noticed improvement, her skin gradually developed uneven pigmentation with scattered white spots.

Clinical assessment revealed melasma with post-laser hypopigmentation. Her treatment plan was adjusted to include medication and therapies aimed at restoring pigmentation.

Her experience highlights the importance of an accurate diagnosis before starting treatment and ongoing assessment of the skin’s response throughout the treatment course.

What is post-laser leukoderma?

Post-laser leukoderma refers to reduced or lost skin pigmentation following laser treatment. It may appear as small pale spots or larger, mottled patches.

Post-laser leukoderma does not necessarily indicate autoimmune vitiligo. Other conditions can also cause lighter patches, so an accurate diagnosis requires a review of the patient’s medical history, previous treatments and clinical findings.

Why can pigmentation become uneven or mottled?

Laser treatment outcomes depend on an accurate diagnosis, the choice of device and treatment settings, treatment technique, cumulative exposure and the individual skin response.

Repeated laser treatments may damage melanocytes—the cells that produce pigment. Some patients develop hypopigmentation alongside persistent or increased pigmentation, resulting in a mottled appearance.

The suitability of further treatment cannot be determined by a fixed interval alone. The skin’s current condition and response to previous sessions must also be considered.

Why does melasma require a broader approach?

Melasma is affected by sun exposure, hormonal factors, and multiple changes within the skin. Treating visible pigment alone may not provide lasting control.

Management commonly includes sun protection, appropriate medication, and ongoing care. Whether laser treatment should be incorporated into the plan depends on an individual assessment.

Can white spots be treated?

The first step is to distinguish areas of increased pigmentation from areas of pigment loss and assess for other underlying conditions.

Depending on the findings, treatment may include medication, phototherapy, or other approaches aimed at restoring pigmentation. Recovery varies; some changes may persist, and complete repigmentation cannot be guaranteed.

Previous treatment records and photographs can help the dermatologist establish when the changes began and how they progressed.

An accurate diagnosis before further treatment

If new white spots or increasingly uneven pigmentation appear after laser treatment, seek a dermatological assessment before proceeding with further sessions.

The goal is to improve pigmentation while maintaining healthy, stable skin.

This article provides general education. Diagnosis and treatment require an individual clinical assessment.