Lasers and pigmentation:
37 questions about diagnosis before device

What is a pico laser?

A laser whose pulses last picoseconds, trillionths of a second. The pulse ends before meaningful heat spreads, so pigment is fragmented by a pressure wave rather than burned, which suits Asian skin, where heat risks post-inflammatory hyperpigmentation.

What is the difference between a pico laser and a Q-switched laser?

Pulse duration. Q-switched lasers work in nanoseconds; picosecond lasers are roughly a thousand times faster, so more of the effect is mechanical and less is thermal. Less collateral heat matters most in darker skin.

How do I know which type of pigmentation I have?

By examination: colour, border, pattern and distribution, how it changes with seasons and hormones, and what preceded it. Magnification or particular lighting helps estimate depth. Many people have more than one type at once.

How can I tell if I have melasma or sun spots?

Melasma tends to be symmetrical with soft, indistinct edges, often hormonally linked and darkening with sun and heat. Solar lentigines are discrete, sharply bordered spots wherever sun exposure accumulated. In-person examination confirms it.

Why did laser make my melasma worse?

Melasma is heat-sensitive; thermal stimulus itself triggers pigment. Settings that suit a sun spot deposit too much heat for melasma, and Fitzpatrick III to V skin readily rebounds. The useful next step is reassessment, not more energy.

Why is my pigmentation darker after laser?

Usually post-inflammatory hyperpigmentation: the laser inflames the skin and melanocytes respond by producing pigment, more readily in Fitzpatrick III to V skin and when settings were too aggressive. If the condition was melasma, heat may have driven it too.

What exactly is laser toning?

Low-fluence 1064 nm Nd:YAG passes repeated over a staged series to gradually even tone and fragment dermal pigment, keeping the surface intact. It is defined by restraint, the opposite of maximum-energy treatment.

Is laser safe for Asian skin tones?

It can be, with protocols suited to Fitzpatrick III to V skin, where the risk of post-inflammatory hyperpigmentation rises if energy is too high. Settings are calibrated to skin tone at every session.

Can enlarged pores be shrunk for good?

No. A pore is the fixed opening of a follicle and oil gland. Treatment changes how large it looks by reducing oil, clearing plugs and supporting the surrounding collagen; keeping that depends on maintenance.

“The laser that clears a sun spot can darken melasma, so the diagnosis has to come before the setting.”

Dr Sin YongOn pigment in Asian skin

What is 少女光 Laser?

Dr Sin Yong's protocol on the DEKA RedTouch Pro, a 675 nm fractional laser absorbed preferentially by collagen rather than water, so it acts on the dermal collagen structure directly, for redness, pores and laxity.

Can pico laser treat melasma safely in Singapore?

Only conservatively, and never as the whole plan. Melasma is chronic and heat-sensitive, so a picosecond laser is at most one adjunct alongside photoprotection, heat avoidance and topical management. Pushed hard, melasma commonly rebounds darker, particularly in Fitzpatrick III to V skin.

What is the difference between PIH and PIE?

Colour, and what sits beneath it. Post-inflammatory hyperpigmentation is a flat brown, grey or slate mark made of pigment. Post-inflammatory erythema is flat pink or red and blanches when a glass is pressed on it, because it is vessels. Pigment treatment does nothing for redness.

Why do brown PIH marks fade faster than grey ones?

Depth. Brown marks hold pigment high in the epidermis, which sheds as skin turns over. Grey or slate marks mean pigment has dropped into the dermis, where immune cells hold it, so they persist far longer. Depth is assessed in clinic and predicts the course.

Will laser get rid of my freckles for good?

No. A pigment-selective laser fragments pigment already in the skin; it does not change the inherited tendency to make freckles, so new ones appear wherever ultraviolet light keeps reaching the skin. Daily sun protection decides how much of the change is kept.

What is Hori's naevus and why is it mistaken for freckles?

Clusters of grey-brown or bluish spots across the cheeks, common in Asian skin, that sit deeper in the dermis than freckles. Because the pigment is dermal, it needs a different wavelength and a longer plan; treating it as a freckle is a common reason a laser course disappoints.

Which pico laser wavelength is used for sun spots?

Usually 532 nm, which melanin absorbs strongly and which stays superficial, where sun spots and freckles sit. 1064 nm travels further with less absorption by surface melanin, so it is the more conservative choice in darker skin; 785 nm sits between the two.

What is a test spot before laser pigmentation treatment?

A small area treated first so the skin's reaction can be watched before a larger area is treated. It is used where the response is uncertain, such as after a recent tan or earlier darkening, and is read after the delay in which PIH appears, not the next morning.

What does fluence mean in laser settings?

Energy delivered per unit area of skin, and the setting that most directly decides how much heat a pulse leaves behind. Raising it can clear a sun spot more decisively and can also inflame the surrounding skin; in melanin-rich skin that margin is narrower.

What does skin look like after pico laser spot treatment?

The treated mark turns darker, sometimes greyish, within minutes, then over several days forms a fine crust, like a speck of coffee grounds, that flakes away on its own. Picking it early risks a mark of its own. Toning, by contrast, usually leaves only redness and warmth.

Can laser toning cause white spots on the face?

It has been reported. Hypopigmentation, seen as pale spots or a mottled pattern, has been described after frequent repeated toning of the same area, which is why toning is staged rather than run on an open-ended schedule. Paling that does not settle is reviewed, not treated over.

What is a long-pulsed alexandrite laser used for?

A 755 nm laser strongly absorbed by melanin, used for dark terminal hair and discrete benign spots such as freckles and lentigines in lighter to medium phototypes. Deeper skin tones are often matched to 1064 nm Nd:YAG instead, and it is not used for melasma, because heat can worsen it.

Does laser toning whiten your skin?

No. It is not a whitening procedure and cannot change natural skin colour. Low-fluence 1064 nm passes act on uneven tone from sun pigment, post-acne marks and, conservatively, melasma; the aim is evenness rather than a lighter base shade, and sun protection decides how much is kept.

Is a chemical peel or laser better for pigmentation?

Depth decides. A peel removes surface layers with acid, so it suits dullness and superficial pigment; laser toning and pico laser send light through a largely intact surface to pigment beneath. In Asian skin deeper peels raise the risk of post-inflammatory darkening. Pigment protocols at this practice are laser-based.

When should a dark spot be checked before laser?

Whenever one spot is the odd one out: darker, larger, growing, irregularly bordered or new in adult life. Lentigo maligna, an early melanoma, can impersonate a sun spot, so that spot earns a dermatoscope examination and a diagnosis before any pigment laser is considered.

Why is heat a trigger for melasma?

Infrared and visible light stimulate melasma independently of UV. A hot yoga class, a kitchen, a steamy walk to the MRT, or a sunscreen that covers UVA and UVB but not visible light can all contribute, and so can a heat-generating laser applied to the wrong diagnosis.

Does sunscreen need to block visible light for melasma?

It helps, because visible light is a trigger in its own right and a clear sunscreen covering UVB and UVA does not address it. Tinted formulations containing iron oxides are commonly used for that reason. Mineral or chemical filters matter less than wearing one daily and reapplying it.

Does haze in Singapore make pigmentation worse?

Studies link fine particulate pollution with pigment spots and skin ageing through oxidative stress, but the evidence is associative rather than settled for any one person. Haze is a second burden on skin already exposed to year-round UV, so sun protection does not pause on a hazy day.

Is there a season for laser pigmentation treatment in Singapore?

Not in the temperate sense. Singapore has no low-UV month, so timing turns on hours and recent exposure instead: a fresh tan or sunburn defers treatment, midday carries the most UV, and protection begins before the first visit rather than after it.

Can a pico laser be used on pigmentation after acne?

Yes, with conditions. Post-inflammatory marks may be treated with low-energy toning once the cause, such as active acne, is controlled, because over-treatment adds pigment rather than removing it. Many of these marks also fade on their own timeline once photoprotection is consistent.

What is the difference between SPF and broad spectrum?

SPF describes protection against UVB, the burning band, and says nothing by itself about UVA, which passes through cloud and window glass and reaches the dermis. A broad-spectrum product carries a separate UVA rating alongside its SPF; both matter for pigment at this latitude.

What happens at a pico laser visit?

Preparation starts before the laser: retinoids and exfoliating acids are paused, sun is avoided, and the pigment is examined and named, with a test patch where the reaction is uncertain. Afterwards expect warmth, possible darkening and flaking, strict sun protection and a review.

Is redness after laser hair removal normal?

Yes. Redness and small raised bumps around each follicle, with a sunburn-like warmth, settle on their own, and treated hairs then shed gradually, which is often mistaken for regrowth. Scabs, blisters, a dark patch or a pale spot are photographed and sent for review.

What happens to the skin after laser tattoo removal?

The area turns white as the laser passes, then red and swollen; blisters can form, dry into scabs and come away to leave pink skin. Leave blisters intact and do not pick; thick yellow crusts, spreading redness, increasing pain or a colour change after healing are reviewed.

What does a mole removal site look like while it heals?

It depends on the method: a laser, radiofrequency or shave site forms a small crust that separates to leave pink skin, while an excision is a sutured line. Sun protection decides whether the new skin darkens; spreading redness, pus or regrowth is not normal.

Am I suitable for laser hair removal?

When the hair carries pigment, the skin is untanned and intact, and nothing in your history makes the skin a risk. Hair colour decides whether there is anything to heat, skin tone decides the wavelength, and hormones decide whether hair keeps coming back.

Is my tattoo suitable for laser removal?

That depends on the ink colours, whether the tattoo was amateur or professional, your skin type and any keloid tendency. Removal is staged and complete clearance cannot be promised, which is discussed before a wavelength is chosen.

What aftercare matters after melasma treatment?

Sun protection against ultraviolet, visible light and heat starts the same day and continues, prescription creams are run as supervised courses, and any patch that darkens after a step is a signal to reassess the plan rather than repeat it.