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The reason why Picosure can be expected to improve even light stains and the difference from phot...




謙太郎 奥
Dr. 謙太郎 奥


American society for laser medicine and surgery (ASLMS) Advisory Board Member of CynoSure, Scientis, L'Oreal Japan Japan Society of Cosmetic Dermatology Japanese Dermatological Association Japanese Society of Anti-Aging Medicine


Medical institution with Dr. Kentaro Oku

Azamino Hills Skin Clinic Azamino Hills Skin Clinic
Contact: 045-507-7420

The reason why Picosure can be expected to improve even light stains and the difference from phototherapy and other laser treatments

Spot treatment includes internal medicine, external medicine, phototherapy, and laser treatment. There are multiple types of lasers used for treatment, but among them, the treatment of spots with picosecond laser (hereinafter referred to as pico laser) can be expected to improve light spots .

The type of laser changes depending on the difference in the "pulse width", which is the irradiation time per shot. In addition to the pico laser, which has a pulse width of pico (1/1 trillion) seconds, nano (1/1 billion) There are Q-switched lasers in seconds, but pico lasers and Q-switched lasers have different effects on the melanin pigment that causes stains. And because of the difference, pico lasers tend to cause less damage to the skin.

Among the multiple pico laser machines, picosure is characterized by its high response to melanin pigments.

Even for light spots, which are said to be more difficult to improve than dark spots, know why Picosure can be improved and how it differs from other treatments, and choose a treatment that you will not regret.

Mechanism and type of stains

The skin is divided into two layers, the epidermis and the dermis, from the top, and spots may form on either of them. The epidermis at the top is made up of four layers, the stratum corneum, the stratum granulosum, the stratum granulosum, and the stratum basale, and is a melanin pigment produced by the pigment cells "melanocytes" that exist in the stratum basale. When it deposits on the skin, it becomes a brown stain.

In addition, when melanin pigment enters and deposits in the dermis layer, which is located below the basal layer, for some reason, blue or dark spots are formed.

The role of "melanin pigment", the cause of age spots

When the skin is exposed to ultraviolet rays, active oxygen that oxidizes the skin cells is generated. When active oxygen increases, skin cells are damaged, so melanocytes produce melanin pigment and act as a "parasol that protects cells" to prevent further UV damage.

The melanin pigment produced is pushed to the upper layers of the skin by turnover, which is normally the metabolism of the skin, and eventually peels off. However, if the turnover cycle is disturbed, the melanin pigment will not be excreted and will accumulate in the epidermis and appear as spots .

Characteristics of each type of stain and how to distinguish it

There are several types of stains, but there are many senile pigmented spots (freckles) and chloasma (chloasma) caused by ultraviolet rays, as well as Ota nevus, post-inflammatory hyperpigmentation, pigmented nevus, There are freckles and so on.

Types of stains color size Part Onset time
Senile pigment spots Light brown to brown 5mm ~ 10mm Places that are easily exposed to light, such as the cheeks From 20s
Chloasma light brown - Inverted triangles are often symmetrical from under the eyes to the cheeks 30s-50s
Ota nevus Blue purple to gray A few mm to a few cm Forehead, eyelids, cheeks, one side of face Within 1 year of age, after puberty
Post-inflammatory hyperpigmentation Light brown to black - Injuries, burns, acne areas, etc. 20s ~
Pigmented nevus Brown to black 1mm-several cm Whole body Infant ~
freckles Light brown to brown 1mm-4mm Nose / cheeks, neck-near décolletage About 5 years old

Liver spots

Senile pigment spots, also known as Nikko Kokushi, are stains caused by the accumulation of excess melanin in the epidermis after continuous exposure to ultraviolet rays.

It is characterized by a clear boundary between the color of age spots and normal skin color, and it begins to appear in the 20s and 30s, and tends to darken or increase in number with aging.


Chloasma is a type of stain that often occurs in women in their 30s and 50s, and is characterized by the fact that it can be symmetrically formed in the range of inverted triangles from under the eyes to the cheeks. The cause is not yet known in detail, but it is said to be caused by many causes such as excessive production of melanin by ultraviolet rays, imbalance of female hormones, and rubbing irritation to the skin.

Ota nevus

Nevus Ota mainly develops within the first year of life and may become darker, or it may develop after puberty. The exact cause has not been elucidated, but it is believed to be caused by abnormalities in melanocytes during the fetal period. As a characteristic of appearance, blue spots such as bruise often appear on one side of the face such as the forehead, cheeks, and around the eyes, and it does not improve naturally.

Normal melanocytes are present in the basal layer of the epidermis and produce melanin pigment in the basal layer, but Ota nevus is manifested by the presence of melanocytes in the dermis and the accumulation of melanin pigment in the dermis. The deeper the melanin pigment accumulates in the deeper layers of the skin, the more bruise-like bluish-purple blemishes become.

Post-inflammatory hyperpigmentation

Post-inflammatory hyperpigmentation refers to age spots caused by the overproduction and accumulation of melanin pigment due to the release of melanocyte stimulants.

Inflammatory cytokines and endothelin, which are melanocyte stimulants, are released during the inflammatory process in the skin caused by acne, wounds, rashes, and insect bites.

Pigmented nevus

Generally recognized as a mole, it can be congenital or acquired. In any case, the exact reason is unknown, but it is believed to be caused by the proliferation of "nevus cells" that resemble melanocytes due to genetic causes.

In the case of congenital giant pigmented nevus, which is as wide as several tens of centimeters, there is a few percent chance that a skin disease called "malignant melanoma" will occur .


Freckles are also called freckles because they resemble the spots on sparrow eggs. It often develops genetically between the ages of 5 and 6, and as it grows, the amount of melanin pigment accumulated increases and freckles tend to become darker in color.

Its appearance is light brown to brown, and it appears in a wide range of small dots on the nose, cheeks, back and arms, which are easily exposed to ultraviolet rays.

Features of lasers used in spot treatment

In addition to internal and external medicines and phototherapy, lasers such as Q-switch lasers, carbon dioxide lasers, and pico lasers are used to treat stains.

Laser (Light Amplification by Stimulated Emission of Radiation) is a type of electromagnetic wave. While light is a collection of multiple wavelengths (colors), a laser is a light beam that is amplified by artificially extracting a specific wavelength, and when absorbed by a specific substance, it produces heat and shock waves. There is.

In aesthetic medicine, a laser with a wavelength that is absorbed by the melanin pigment that causes the stain is used to destroy the melanin pigment with heat or shock waves, leading to improvement of the stain.

Destructive power increases as the laser irradiation time becomes shorter

The time that one laser hits the skin (irradiation time) is called the "pulse width", and the pulse width of the laser used in laser treatment is extremely short, such as milliseconds, microseconds, nanoseconds, and picoseconds.

Milliseconds (ms) 1 / 1,000s: Long pulse
Microseconds (μs) 1 / 1,000,000s (1 / 1,000,000 second)
Nanoseconds (ns) 1 / 1,000,000,000s (1 billionth of a second)
Picoseconds (ps) 1 / 1,000,000,000,000s (1 / trillionth of a second)

The pulse width varies from laser machine to laser machine, and the shorter the pulse width, the greater the instantaneous force acting on the substance and the greater the destructive force .

Lasers with pulse widths of milliseconds, microseconds, and nanoseconds generate heat in a substance when irradiated, and the heat destroys the object. If you irradiate the laser strongly to increase the destructive power, heat will be transferred to the surrounding cells, increasing the possibility of side effects such as post-inflammatory hyperpigmentation and burns.

Short pulse width reduces the risk of skin tissue damage On the other hand, a pico laser with a pulse width of picoseconds generates a shock wave in a substance when irradiated, and can crush the target finely. Since the destructive power of the shock wave is very large, even if you do not irradiate the laser strongly, it will crush the melanin that causes the stain and lead to the improvement of the stain. Pico laser is a shock wave that has less influence on the surroundings than heat and does not require strong irradiation, so it does not cause unnecessary damage to surrounding cells, so side effects such as post-inflammatory hyperpigmentation are less likely to occur.

Laser wavelength selected according to skin problems

Electromagnetic waves including lasers are the energy of waveforms that repeat peaks and valleys, and the length of the waveform peaks to peaks (or valleys to valleys) is called the wavelength.

Wavelengths are expressed in units of nanometers (nm), which is one billionth of a meter, and there are different types of lasers, such as 694 nm ruby lasers and 755 nm alexandrite lasers, depending on the wavelength.

In addition, since the substances that are easily absorbed differ depending on the wavelength (laser), treatment is performed using a laser that has a wavelength that matches the skin's problems.

Picosure, an alexandrite laser, has a wavelength of 755 m and is easily absorbed by melanin pigments .

Picosure that can be expected to improve light spots

Picosure_Picosure that can be expected to improve light spots Picosure is a pico laser machine developed by Cynosure of the United States. It is a medical device approved by the Ministry of Health, Labor and Welfare, and has been shown to be effective in treating spots and removing tattoos. In addition, the US FDA (US Food and Drug Administration), which is the Ministry of Health, Labor and Welfare of Japan, has approved the effects of improving spots, wrinkles, and acne scars and removing tattoos. Currently, it has been approved in Japan, and some cases are covered by insurance.

Wavelength that can be irradiated 532nm, 755nm, 1064nm
Pulse width that can be irradiated Picoseconds (1/1 trillion seconds)
Spots that can be expected to be effective Senile pigmented spots, chloasma, nevus Ota, post-inflammatory hyperpigmentation, pigmented nevus, freckles

Picosure is a pico laser that can crush melanin pigments

Melanin pigment crushing

Spots become darker as the number of melanin pigments accumulated in the epidermis increases, and become lighter as the number of melanin pigments accumulates in the epidermis . In other words, the darker the stain, the easier it is to aim as a target, but the lighter the stain, the more difficult it is to improve .

However, with a pico laser with a short pulse width, it is possible to crush the melanin pigment even with a light stain by a shock wave.

Q-switched laser Pico laser
pulse width Nano (1/1 billion) seconds Pico (1/1 trillion) seconds
How to destroy melanin pigment heat shock wave
downtime Thick scabs for 1-2 weeks, need tape protection A thin scab may form for a day to a week, but no tape protection is required

The melanin pigment, which is finely crushed by picosure, is excreted by turnover, which is the metabolism of skin cells, and is also excreted from the body via lymphatic vessels and blood vessels by being preyed on by macrophages, which are immune cells.

In addition, the finer the melanin pigment is crushed, the easier it is to be discharged. Therefore, it can be expected that the pico laser stain treatment will discharge the melanin pigment more efficiently than the Q-switched laser.

Picosure wavelength is 755nm, which easily reacts with melanin pigment

In addition to Picosure, there are several machines with pulse widths in picoseconds, but each has a different wavelength. Each wavelength has certain substances that are easily absorbed, and for spot treatment it is necessary to select a machine with a wavelength that responds well to melanin pigments.

Picosure can treat blemishes at a wavelength of 755 nm (Alexandrite laser), which is said to react well with melanin pigments.

Of the wavelengths used in laser treatment in aesthetic medicine, the one that is most easily absorbed by melanin pigments is 532 nm (KTP laser), which is not actually 755 nm. However, 532nm also reacts (easily absorbs) hemoglobin contained in blood vessels, so almost all people have a scab, and there is a high possibility of internal bleeding and erythema.

For this reason, 755 nm wavelengths, which are less burdensome to the skin, are often selected for spot treatment.

Picosure that uses three types of irradiation properly depending on the purpose

Picosure has three irradiation methods: toning irradiation, fractional irradiation, and spot irradiation, and you can perform treatment according to your symptoms by using different irradiation methods.

It is also possible to perform treatment by combining three irradiation methods.

Irradiation method Application Target size that can be aimed at by irradiation Application to light spots
Toning irradiation Uneven skin color, dullness, chloasma 4.0mm-6.0mm (adjustable in 0.1mm increments), 8.0mm, 10.0mm
Fractional irradiation Opening of pores, acne scars, fine wrinkles 6.0mm, 8.0mm, 10.0mm
Spot irradiation Spots, freckles, tattoos 2.0mm-6.0mm (adjustable in 0.1mm increments)
Combination irradiation Uneven skin tone, dullness, chloasma pores, acne scars, fine wrinkles, freckles 2.0mm-6.0mm (adjustable in 0.1mm increments)
6.0mm, 8.0mm, 10.0mm

Toning irradiation

Toning irradiation is a method of irradiating the entire skin with 2000 to 4000 shots per treatment with low output.

By stimulating the melanin pigments in the epidermis and dermis layers and decomposing and discharging the melanin pigments, the effect of brightening the skin tone can be expected. It can be expected to have the effect of improving and brightening freckles and uneven-colored skin.

Fractional irradiation

Fractional is a method of irradiating the skin with a laser in fine dots using a focus lens that can focus the laser on one point.

By giving a special stimulus to the epidermis layer and the dermis layer, the turnover cycle is arranged in the epidermis layer, and the production of hyaluronic acid, collagen, and elastin is promoted in the dermis layer .

In the dermis layer, collagen, which is a fibrous protein, is bundled by the protein elastin, and jelly-like hyaluronic acid fills the space between them while holding water. By promoting the production of these substances that make up the dermis layer, the skin will self-regenerate, and it is possible to improve fine wrinkles, acne scars, and pore opening.

Spot irradiation

Compared to toning irradiation and fractional irradiation, spot irradiation has a higher irradiation output, and the laser irradiation range can be finely adjusted in 0.1 mm increments. Therefore, it is possible to focus on the spots you care about and irradiate them with pinpoint. Since the output of the laser to irradiate is strong, there is pain like a rubber band during the procedure, so if you are not good at pain, it is safe to check with a medical institution for anesthesia.

Number and frequency of treatments required for treatment of light spots with Picosure

In the case of treatment of light spots with Picosure, the spots tend to become lighter and less noticeable within 7 to 10 days after the treatment. In some cases, you can feel the effect even with one treatment, but it is more effective if you repeat the treatment 1 to 5 times depending on the condition of the spots.

Once every 4 weeks when receiving repeated treatments at Picosure

In the treatment of age spots with Picosure, it is possible to efficiently promote the excretion of melanin pigment by receiving treatment according to the turnover cycle of the skin. However, stimulating the affected area after laser irradiation can cause post-inflammatory hyperpigmentation . For this reason, most medical institutions indicate that it is necessary to leave an interval of about 4 weeks when receiving repeated treatments.

In addition, even if the timing of re-irradiation is vacant for more than one month, the effect of treatment will not be affected.

Flow of spot treatment by Picosure

(1) Counseling / examination / filling out a questionnaire

Tell the doctor what you want to talk about, the part you care about, the symptoms, etc., and decide on a treatment policy.

(2) Cleansing / face washing

Cleanse to remove makeup and wash your face to cleanse your skin. Some medical institutions take pictures of the condition of the skin before the procedure.

(3) Treatment

Depending on the medical institution, laser irradiation is performed after applying anesthesia. After irradiation, the treatment area is cooled.

(4) Treatment

If it is toning irradiation or fractional irradiation, you can make up after the treatment. In the case of spot irradiation, makeup will be available from the next day.

Downtime risk and precautions for treating light spots with Picosure

Downtime and risk

Unlike pico lasers, spot treatment with a Q-switched laser destroys the melanin pigment by heat rather than shock waves, but since the heat spreads around the spot, side effects such as post-inflammatory hyperpigmentation and burns may occur. there is. As a guide, downtime of 1 to 2 weeks is required, and it is common to put a protective sticker on the affected area after the treatment.

On the other hand, PicoSure crushes the melanin pigment with a shock wave generated by irradiation with a very short pulse width of picoseconds, so there is less damage to the skin tissue around the stain and the burden on the skin is reduced . In addition, it is not necessary to put a sticker on the irradiated area to protect it even after the treatment.

Immediately after irradiation to 24 hours There is a hot spot on the face
2-3 days A scab may form on the irradiated area
4-6 days If a scab occurs, it will start to peel off
7-10 days The scab peels off, making the stains less noticeable and thinner

Compared to Q-switched lasers, Picosure has a lower risk of redness and scabs, and has almost no downtime.

However, laser treatment is performed for symptoms that cannot be expected to improve, such as spot irradiation on areas with "chloasma" that may be aggravated by irritation , UV protection, sufficient moisturization, etc. If you neglect to take aftercare after the treatment, there is a risk that the symptoms will worsen, such as darkening of spots. Other risks that can occur with the procedure include the following.

Post-inflammatory hyperpigmentation

Melanocytes tend to be activated by these stimuli in areas that are easily exposed to ultraviolet rays, such as the forehead and cheeks, and areas that are prone to friction due to clothes and masks. When melanocytes that produce melanin pigment become active, melanin pigment can be overproduced and deposited in the epidermis and dermis layers, causing pigmentation.

Therefore, after receiving the treatment, it is important to shield the affected area from UV rays and not to touch the irradiated area more than necessary to stimulate it.


Since spot treatment with Picosure stimulates the skin by laser irradiation, the irradiated area may become reddish for about 10 hours immediately after irradiation. When redness occurs, it can be alleviated by cooling the affected area and refraining from actions that promote blood circulation such as bathing and strenuous exercise .


Facial redness often disappears over time, but in rare cases scabs may occur.


If you try to forcibly remove the scab, bacteria may enter the wound and cause infection, so do not forcibly remove it.

Other risks

  • Burns / blisters
  • Depigmentation
  • Petechiae in the skin (no blood comes out of the skin)

Those who cannot receive Picosure treatment

  • Pregnant / lactating
  • Those who have gold thread
  • Those with photosensitivity
  • Keloid constitution
  • Those who are receiving some oral treatment (isotretinoin)
  • Those who have inflammation, scars, or herpes at the treatment site
  • Those who have a sunburn within 4 weeks before the procedure
  • Those who received laser treatment or phototherapy within 4 weeks
  • Those who received botulinum injection within 1 week

Treatment methods other than Picosure that can be expected to improve light spots

Treatment method with pico laser irradiation machine

There are five main pico laser machines that can be expected to improve light spots other than picosure.

wavelength pulse width Approval of public institutions
Picoway 532 nm / 730 nm / 1064 nm 294 ps / 246 ps / 339 ps FDA, Ministry of Health, Labor and Welfare
Enlighten 3 532 nm / 670 nm / 1064 nm 750 ps / 660 ps / 2 ns
Discovery Pico 532 nm / 694 nm / 1064 nm 370 ps / 30 ns / 450 ps Ministry of Health, Labor and Welfare
Spectrapico 532nm / 595nm / 660nm / 1064nm 750ps / 2ns
Pico care 532nm / 595nm / 660nm / 1064nm 450ps FDA
(By removing tattoos)

Treatment method with internal and external medicines

Depending on the medical institution, treatment may be performed using the following internal or external medicines before or after laser treatment or in parallel with laser treatment.

Oral medicine

  • Tranexamic acid
  • Vitamin C
  • Dartation
  • Cysteine

By taking an internal medicine that suppresses pigmentation, the active ingredient is carried into the bloodstream and reaches the skin, suppressing the activation of melanocytes that produce melanin pigment .

External medicine

  • Hydroquinone
  • Tretinoin
  • Kojic acid
  • Vitamin C

By applying an external medicine, it acts on melanocytes and can suppress the overproduction of melanin.

Hydroquinone can be expected to be effective when used in combination with tretinoin, which has a high melanin pigment excretion effect. When used alone with hydroquinone, it is more likely to cause dermatitis such as rashes, and tretinoin may cause peeling during melanin pigment excretion. Please protect and use.

Daily skin care is also important to improve light spots

Treatment of age spots with a laser machine such as Picosure is expected to improve by receiving treatment with a wavelength and pulse width suitable for each type of age spot, amount of melanin pigment, and depth of skin where melanin pigment is accumulated. I can do it.

The pico laser can be expected to crush the melanin pigment into small pieces and improve light spots if it is irradiated based on the correct diagnosis of the doctor, but if the treatment is performed by an incorrect diagnosis, post-inflammatory hyperpigmentation will occur at the irradiated site. It may also appear that the stains are darker. Therefore, it is important to receive treatment by a doctor who has a wealth of experience in treating spots and is familiar with the characteristics of the machine .

In addition, skin care and lifestyle changes may be expected to prevent or improve age spots, so take proper measures against UV rays, prevent rubbing irritation on the skin, improve sleep quality, and be careful about your diet. It is also effective to review your daily habits .

Treatment of light spots at Azamino Hills Skin Clinic

Dr. Kentaro Oku, who supervised the article, taught me about the treatment of light spots.

Please tell us about Picosure, which can be expected to improve even with light stains.
Mr. Kentaro Oku
Light spots are difficult to improve with long pulse width phototherapy or nanosecond lasers due to the small number of melanin pigments, but picosure is a wavelength that is easily absorbed by melanin pigments, and even a small amount of melanin pigments. Even if there is, it can be crushed with a shock wave, so even light stains can be expected to improve.
Can the stains worsen after treatment with Picosure?
Mr. Kentaro Oku
After the treatment, it is important to take proper measures against UV rays and moisturize, and if this aftercare is neglected, the stains may become dark. In addition, spot irradiation of chloasma, which is said to be aggravated by irritation, may cause darkening of the color, so an accurate diagnosis is required.
Is there anything I should be careful about to get an accurate diagnosis?
Mr. Kentaro Oku
Medical treatment that not only visually checks whether the skin is inflamed or damaged, but also grasps the condition of the skin before and after the treatment with a skin diagnostic imaging device and proposes treatment contents tailored to each individual according to the symptoms of age spots. You should choose an institution.
What is the price of Picosure at Azamino Hills Skin Clinic?
Mr. Kentaro Oku
It costs 27,500 yen (tax excluded price 25,000 yen) for toning irradiation, 38,500 yen (tax excluded price 35,000 yen) for fractional irradiation, and 55,000 yen (tax excluded price 50,000 yen) for spot irradiation. Treatment is performed by combining irradiation methods according to the skin symptoms.
Please give a message to those who receive spot treatment.
Mr. Kentaro Oku
Blemishes are the result of daily skin damage. Whether it is light or dark spots, treatment with Picosure can lead to improvement, but it is also important to create skin that is difficult to make spots. Let's grow beautiful skin in the best way for each person by combining skin care and laser treatment.
Thank you, Mr. Oku.

Introduction of supervising doctor

Dr. Kentaro Oku, director of the Azamino Hills Skin Clinic and an Advisory Board Member at CynoSure, the largest medical laser manufacturer in the United States that developed Picosure. We have abundant experience in picosure treatment, and the clinical results of picosure are as high as 5,000 cases. Many foreign doctors come to Japan just to attend the seminars of Oku-ishi, and their knowledge and high technical capabilities are highly trusted not only in Japan but also overseas.

Medical institution with Dr. Kentaro Oku

Azamino Hills Skin Clinic Azamino Hills Skin Clinic
Contact: 045-507-7420