Not All Dark Spots Are the Same! 6 Types of Pigmentation You Must Identify Before Your Laser Treatment

As the end of the year approaches, many people add "laser spot removal" to their annual beauty maintenance list. However, dermatologists warn that before rushing into aesthetic treatments, an accurate diagnosis is crucial.

The causes of clinical "dark spots" are complex, and not all are suitable for direct laser treatment. Proceeding without a professional diagnosis may not only be ineffective but could also worsen the condition.

Dark Spots ≠ Just a Cosmetic Issue

Dr. Chau Yee Ng (MD, PhD) emphasizes that clinical dark spots generally fall into three categories: physiological (aging, sun exposure), disease-related (hormonal, immune, viral), and "malignant lesions" that must be ruled out first.

Lack of diagnosis by a dermatologist may delay necessary treatment for underlying conditions. As illustrated in the image, here is an explanation of the 6 common types (from top left to bottom right):

1. Seborrheic Keratosis (Age Spots)

Characterized by a rough surface, appearing like a brown or black plaque that is "stuck" onto the skin. These are benign keratin overgrowths associated with aging and sun exposure. Treatments include laser, cryotherapy, or electrocautery. They are not malignant.

2. Melasma

Often symmetrically distributed on the cheeks, zygoma (cheekbones), and forehead. Melasma is highly correlated with hormonal changes, UV exposure, and chronic inflammation.

Doctor’s View: The focus of treating Melasma is not on forcefully "removing" it, but on regulating inflammation, avoiding irritation, and long-term management.

3. Solar Lentigo (Sun Spots)

Caused by chronic sun exposure, featuring distinct borders and relatively uniform color. Provided the skin condition is stable, a combination of sun protection, laser, and topical agents usually yields good results.

4. Flat Warts (Verruca Plana)

Caused by the HPV virus. While they look like ordinary spots, they are actually viral warts.

Doctor’s Warning: Lasers must not be used indiscriminately on these lesions; otherwise, the virus can easily spread. Proper diagnosis and antiviral treatment are required first.

5. Nevus of Ota

Usually presents as a unilateral, blue-grey, or dark brown patch, commonly found around the eye and cheekbone. This is a pigmentation issue within the dermis (deeper skin layer) and requires deep-layer laser treatment, differing completely from superficial spot treatments.

6. Melanoma

This requires the highest level of vigilance. If a spot shows color irregularity, irregular borders, rapid growth, bleeding, or ulceration:

Key Action: The first step is absolutely not laser, but a pathological examination (biopsy).

Special Reminder: Laser Risks for Vitiligo Patients

Dr. Chau Yee Ng specifically reminds patients with Vitiligo: If you wish to treat dark spots surrounding or coexisting with vitiligo patches, you must first confirm that your vitiligo is in a "stable phase."

Laser treatment may trigger an immune response, leading to the Koebner phenomenon, causing the vitiligo to spread. Therefore, close follow-up is necessary after treatment, potentially combined with medication to prevent the reactivation of immune cells.

Conclusion: Medical Care First, Aesthetics Second

"The role of medicine is not just choosing 'which laser,' but first distinguishing—'can we laser?'"

Dr. Ng concludes that only through correct diagnosis—ruling out malignancies and infectious diseases—and tailoring treatment to individual skin conditions, can beauty be restored safely.