脫墨除痣有很多方法。包括電燒灼，冷凍治療，以及藥水腐蝕，激光去除，手術切除等等。
1. 電燒灼脫墨就是把以電流發熱的微細電線掂住長有癦痣的皮膚表面。這方法可以以熱力把墨痣細胞破壞（電燶），達致脫墨目的。但是它的缺點就是周邊破壞大，令到附近沒有墨／痣細胞的正常皮膚受到破壞。令到疤痕的表面面積比起粒墨大很多。而且其深度非常難控制，不是太淺，就是太深。由於周邊破壞大，所以以此脫細小的墨痣會造成較大的疤痕。而且結焦的地方並不能聯線，因此用這方法來脫比較大的墨痣也很難有漂亮的疤痕。
2. 冷凍治療一般使用液態氮氣。把液化的氮氣接觸皮膚有墨痣的地方破壞墨痣細胞。這個脫墨方法就更差。周邊破壞更加闊，深度更加難控制。唯一好處就是它的成本比電燒灼平。
3. 藥水腐蝕脫墨使用酸性或鹼性藥水破壞墨痣細胞。這個方法脫墨疤痕最大。但是這個方法是所有方法之中最平。
4. 激光脫墨應該係現時最靚的方法。唯一缺點就是成本最貴。所以如果單從外觀的原因，即係醫學美容原因，我們通常會選擇激光脫墨，而不會使用電燒灼，冷凍，或腐蝕性藥水等等比較原始的方法。但是並非所有人都可以做激光脫墨。如果墨痣屬於惡性（即係皮膚癌），就不可以用激光或其他方法，應當用手術方法切除。
為咗美容目的而做脫墨（通常細小的墨痣）的，通常用激光，而最常用的脫墨激光，就係二氧化碳激光（波長10600納米）。二氧化碳激光可以很有效地被水分子吸收，從而把目標組織氣化，而不是燒焦。激光將墨痣的細胞一層一層的氣化。直達墨痣的根部。因為激光有良好的熱凝固功效，操作激光的時候，沒有流血，也沒有結焦，所以可以清楚看見墨痣的根部。不會因為打得太深引起疤痕，也不會因為打得太淺而未能把墨痣脫乾淨。因為激光的光線可以聚焦，所以激光造成的周邊破壞非常之少。而其他方法，例如電燒灼，腐蝕性藥水， 以及冷凍等等這些方法，操作時的周邊破壞比較大，引致附近正常組織受到不必要的破壞，所以造成的疤痕就比較寬大難看。而且這些方法，操作的時候沒法可以看到墨痣的根部。得出來的傷口，不是太過深（有疤），就是太過淺（未乾淨）。
（作者後面啲四部機器全部都是二氧化碳激光機）
There are several methods for mole removal, including electrocautery, cryotherapy, chemical corrosion, CO2 laser cauterisation, and surgical excision.
Electrocautery involves using a fine, heated wire powered by electricity to touch the mole on the skin’s surface. The heat destroys the melanocytes (the mole cells) (essentially “burns” them off). However, this method can cause significant damage to the surrounding healthy skin (peripheral damage), resulting in scars that are often larger than the original mole. It’s also difficult to control the depth of destruction—it often ends up being either too shallow or too deep. Because of this, using electrocautery for small moles can result in disproportionately large scars, and larger moles can’t be removed cleanly with this method.
Cryotherapy usually employs liquid nitrogen. It destroys the mole cells by freezing the affected area. However, it causes even more widespread damage around the target area and is even harder to control in terms of depth. Its only advantage is that it’s more affordable than electrocautery. The claim of this treatment being less painful is actually not true.
Chemical corrosion involves applying acidic or alkaline solutions to destroy mole cells. This method generally leaves the most noticeable and extensive scarring, though it is the cheapest of all methods.
Laser removal is considered the most refined method today, albeit the most expensive. For cosmetic or aesthetic purposes, laser mole removal is typically preferred over the more primitive methods like electrocautery, cryotherapy, and chemical corrosion. However, laser removal is not suitable for malignant skin lesions (i.e., skin cancer)—in such cases, surgical excision is necessary.
For cosmetic/aesthetic mole removal (especially smaller moles), CO₂ laser (wavelength 10,600 nm) is the most commonly used. This laser is efficiently absorbed by water molecules, allowing it to vaporize the target tissue instead of burning it. The laser removes the mole cells layer by layer, right down to the root without burnt crusts being formed. Thanks to its excellent thermal coagulation, there’s no bleeding, allowing the root of the mole to be clearly visible during the procedure. This accuracy minimizes scarring—no overly deep wounds, and no incomplete removals due to insufficient depth.
Because the laser beam is highly focused, damage to the surrounding healthy tissue is minimal—unlike with electrocautery, corrosive chemicals, or cryotherapy, all of which tend to affect a larger area of nearby healthy skin and often result in wider, unsightly scars. Moreover, with those methods, it’s not possible to clearly visualise the mole’s root/mole cells during treatment, leading to wounds that are either too deep (scarring) or too shallow (leaving mole remnants behind).
另外一隻脫墨激光就係Er:YAG 激光（波長2940納米）。它沒有二氧化碳激光咁好。因為它的穿透力，比起二氧化碳激光細，所以很難直達墨痣的根部。所以Er:YAG 激光比較少人用。
5. 手術切除方法，就係直接吧該墨痣切出來。切割的時候，會根據病灶的本質，去決定切除多少正常的組織。比較良性的腫瘤不會切去太多正常組織，而比較惡性的，就會切去較多正常組織）。因為切除的地方比起該墨痣範圍（或稱病灶）為大，所以傷口及疤痕都係比較大的。疤痕亦不會太好看。某種比較惡性的皮膚癌，就需要切除更多的正常組織，疤痕就會更大。切出來的組織，會做切片化驗，已確定是那一種皮膚腫瘤，之後再決定治療方法。良性的墨痣，用手術方法切除，復發率一般比其他所有方法都低。
（以下三張照片就是手術切割墨痣的過程）
Another type of laser used for mole removal is the Er:YAG laser (wavelength 2940 nm). However, it’s generally considered less effective than the CO₂ laser. The Er:YAG laser has less penetrating power, which makes it harder to reach the deeper part of the mole. Because of this limitation, it’s not as commonly used.
5. Surgical excision involves cutting out the mole with scalpel. During the procedure, the amount of normal tissue removed depends on the nature of the lesion. For benign tumors, only a small margin of healthy tissue is removed. For malignant lesions, a wider margin of surrounding tissue is taken. Since the area removed is larger than the mole, the resulting wound and scar are larger, and usually not very aesthetically pleasing.
In certain types of malignant skin cancers, even more surrounding tissue must be excised, resulting in an even bigger scar. The removed tissue is sent for histopathological analysis to determine the exact type of skin tumor, which then guides further treatment. For benign moles, surgical excision typically has the lowest recurrence rate of all removal methods.
(The following three photos show the process of surgical mole excision )
激光脫墨的復發率比手術切割高，但在有經驗的醫生手中，九成以上可以一次清除乾淨。激光脫墨的傷口比較細小，因為激光造成的周邊破壞比較細，這個細小的傷口會在幾天之後結焦，一兩個星期之後甩焦。甩焦之後，剛剛復原的傷口會呈粉紅色或咖啡色。這個叫做色素沉着。皮膚比較黑的人，這個色素沉着會比較嚴重。而且持續的時間比較耐。大部份這種色素沉着都會自動退去。只有少數是永久的。有時候因為傷口太過深，疤痕會呈現一個凹陷的狀態。有時候，疤痕會呈現一個突出的狀態稱之為疤痕增生。
（以下圖片就是激光脫墨的效果）
Laser mole removal has a higher recurrence rate compared to surgical excision, but in the hands of an experienced doctor, over 90% of cases can be fully cleared in a single session. Laser removal results in smaller wounds because it causes minimal damage to surrounding tissue. These small wounds typically form a scab within a few days, which falls off after one or two weeks.
After the scab sheds, the newly healed skin often appears pink or brown, a condition known as post-inflammatory hyperpigmentation. People with darker skin tones may experience more noticeable pigmentation, and it may last longer. In most cases, this pigmentation fades without treatments over time, though in rare instances it can become permanent.
In some cases, if the wound is very deep, the resulting scar may be depressed. Sometimes, a scar may become raised, and this is known as hypertrophic scarring or keloid scarring.
(The following image shows the results of laser mole removal.)
總結：各種脫墨方法（激光、電灼、腐蝕藥水等）利弊分明。雙碩士醫生懂得因痣制宜，最大程度減低疤痕；美容院常用舊式手法，效果與美觀皆失。對於一些新的技術，它又未能掌握。非醫生如果在美容院內施行手術更可能會觸犯法例。
（以下圖片就是激光脫墨的效果）
Conclusion: Each technique has risks and limitations. A medical doctor with master’s training in both skin pathology and medical aesthetics is uniquely qualified to choose the safest, most effective method tailored to your needs.