TCA Cross Acne Scars

Acne scars, particularly deep ice pick and boxcar scars, can be among the most stubborn reminders of a past breakout. Dr. Michele Green in New York City is a nationally recognized expert in acne scar treatment, offering a full range of cosmetic solutions, including laser resurfacing, chemical peels, microneedling, dermal fillers, subcision, and TCA CROSS to smooth atrophic acne scars and restore an even skin texture. TCA CROSS, or chemical reconstruction of skin scars, is an advanced technique mastered by a few dermatologists. Dr. Green has refined its use for patients of every skin type and skin tone, including Asian, Hispanic, Caucasian, and darker complexions.

For over two decades, Dr. Green has used TCA CROSS to treat acne scars by applying a highly concentrated trichloroacetic acid directly to individual scar depressions with a fine applicator, stimulating new collagen production and gradually smoothing the skin’s surface. TCA CROSS works especially well for atrophic acne scars, such as ice pick acne scars and boxcar scars. Because the treatment carries some risk of hyperpigmentation or scarring if performed incorrectly, it should always be performed by an experienced, board-certified dermatologist, such as Dr. Green in New York City.

Dr. Michele Green is an internationally renowned, board-certified dermatologist specializing in treating acne scarring and skin discoloration. With over 25 years of experience, Dr. Green offers some of the world’s most discerning patients today’s best non-invasive skin rejuvenation options, including TCA CROSS for atrophic, rolling, hypertrophic, and keloid acne scars. During your consultation, Dr. Green will design a customized acne scar treatment plan tailored to your skin type, skin tone, and specific scarring pattern.

What is TCA CROSS?

TCA stands for trichloroacetic acid, the same chemical Dr. Green uses for chemical peels and TCA CROSS treatment. “CROSS” stands for chemical reconstruction of skin scars, a technique in which a strong concentration of trichloroacetic acid is applied directly to individual atrophic scars. A Korean dermatologist first developed TCA CROSS, which is especially well-suited to ice pick scars, though it is also used for boxcar and rolling scars. Minute amounts of high-concentration TCA are deposited directly into each scar depression to stimulate new collagen and elastin production. TCA CROSS is not recommended for skin types 3 or darker, and most patients require 3 to 5 sessions spaced 6 to 8 weeks apart for optimal results. For some patients, TCA CROSS improves atrophic scars more than laser resurfacing, and the treatment causes only minimal discomfort.

What are the 3 main types of acne scars?

Acne scarring generally falls into three main categories, each of which forms differently and responds best to a different combination of treatments. During your consultation, Dr. Green identifies which type or types of scarring are present so she can recommend the most effective approach for your skin.

Atrophic Scars

Atrophic scars are the most common type of acne scarring and form when the skin doesn’t produce enough collagen during healing, leaving a depression or indentation where the acne lesion once was. They are further divided into three subtypes:

• Ice-pick scars – These account for roughly 60% of atrophic scarring and are narrow, deep, and shaped like a puncture wound, making them some of the most difficult acne scars to treat.
• Boxcar scars – These make up about 25% of atrophic scarring and appear as round or oval depressions with sharply defined, box-like edges.
• Rolling scars, which account for roughly 15% of atrophic scarring and create a wave-like, undulating texture in the skin due to fibrous bands tethering the skin to deeper tissue.

TCA Cross, subcision, microneedling, and dermal fillers are all commonly used to treat atrophic acne scars.

Hypertrophic Scars

Hypertrophic scars form when the skin produces too much collagen while healing from an acne lesion, resulting in a raised, thickened area of scar tissue that stays within the original borders of the wound. Unlike atrophic scars, which create a depression in the skin, hypertrophic scars sit above the surrounding skin and can feel firm or rope-like. They are more likely to develop on the chest, back, and jawline, where acne lesions tend to be deeper and more inflamed. Hypertrophic scars often respond well to laser resurfacing, corticosteroid injections, and other treatments that soften and flatten raised scar tissue.

Keloid Scars

Keloid scars are a more severe form of raised scarring in which excess collagen continues to grow beyond the original borders of the acne lesion, sometimes forming a scar that is significantly larger than the wound that caused it. Keloids are more common in patients with darker skin tones, often have a genetic predisposition, and can be itchy, tender, or cosmetically bothersome. Because keloids can worsen with certain treatments, including TCA CROSS, they require a carefully tailored approach, such as corticosteroid injections, laser treatment, or surgical revision, under the guidance of an experienced board-certified dermatologist like Dr. Green.

Does TCA CROSS work for acne scars?

Yes. In many cases, TCA CROSS is more effective for certain atrophic acne scars than laser resurfacing. Darker skin types typically require a weaker 50% TCA solution rather than the 100% concentration used for lighter skin. Because the acid is less aggressive at that strength, you may need more sessions to achieve the desired improvement. The exact concentration depends on the scar type and the patient’s skin type; meticulous technique is essential to avoid pigmentation changes or worsening scarring. Dr. Green commonly prescribes hydroquinone for darker-skinned patients both before treatment and for several weeks afterward to prevent and treat post-inflammatory hyperpigmentation.

How does TCA CROSS work for ice-pick scars?

TCA CROSS targets the scar depression itself rather than the surrounding skin. The acid is applied precisely with the edge of a syringe or a toothpick-style applicator directly into the atrophic scar, leaving the surrounding healthy skin untouched. The technique can also improve the appearance of enlarged pores and boxcar scars. Depending on skin type and scar depth, practitioners may use concentrations up to 100% TCA, with recovery generally taking less than a week. Afterward, special emollients, sunscreen, and strict sun avoidance help prevent hyperpigmentation. TCA CROSS can also be paired with dermal filler injections, such as Juvederm, Restylane, and Sculptra, or with other laser treatments. At the cellular level, TCA CROSS denatures old collagen in the scar tissue. It triggers new, healthy collagen production, which begins forming within about 4 weeks and continues to remodel the scar depressions for up to 4 months after each session.

How is the TCA CROSS technique performed?

Before your TCA CROSS treatment, Dr. Green will often perform a test spot on a small area of scarring to assess how your skin responds to the acid concentration before treating the rest of your face. The full procedure follows a precise sequence:

• At the start of the procedure, the skin is degreased with alcohol before applying any trichloroacetic acid.
• Photos are taken of the treatment area to document the procedure’s progress.
• Each scar is carefully treated with between 50 and 100% TCA, and each area is neutralized with water directly after treatment.
• After the acid is applied, you will observe frosting of the skin where the treated area initially turns white and later red.
• Each atrophic scar is treated with the acid on a wooden applicator, toothpick, or insulin syringe.
• Each lesion then scabs after a few days, creating wounds that heal to generate new skin.
• The entire treatment takes between 15 and 30 minutes, depending on the amount of acne scarring.
• Proper skin care and sun protection are reviewed after the procedure, and strict sun avoidance is recommended.
• Downtime is generally 5 to 7 days.
• Hydroquinone creams are commonly prescribed for darker skin patients.
• Refrain from makeup after the procedure for several days until the skin heals and returns to normal. Lycogel may be used post-laser.

Procedures that can be performed with TCA CROSS

Treating acne scars usually calls for a combination of treatments. While TCA CROSS can be used alone for some patients with atrophic scars, many benefit from pairing it with other procedures, including:

Subcision

Subcision is often combined with TCA CROSS to release fibrous bands that tether rolling scars beneath the skin, allowing the scarred tissue to lift while TCA CROSS addresses surface texture.

Microneedling with Dermapen or Eclipse Micropen

Microneedling stimulates collagen production over a broader area of scarring and pairs well with TCA CROSS’s more targeted, spot-treatment approach for individual ice-pick scars.

Microneedling with Depigmentation Serum

Microneedling with a depigmentation serum creates temporary microchannels that enhance absorption of skin-brightening ingredients, helping fade post-inflammatory hyperpigmentation around treated scars, while TCA CROSS addresses the depth of the scars themselves.

Platelet Rich Plasma Microneedling

PRP facials use the patient’s own growth factors to accelerate healing and enhance collagen remodeling. They are frequently layered over microneedling or TCA CROSS sessions to boost results.

Fraxel Laser

Fraxel fractional laser treatment resurfaces the skin in a controlled pattern and is often alternated with TCA CROSS sessions to address both diffuse textural irregularities and deeper individual scars.

eMatrix Laser

eMatrix radiofrequency laser treatment combines fractional resurfacing with thermal energy to stimulate deeper collagen production, making it a useful complement for patients with mixed scar depths.

Punch Excision

Punch excision removes deep, narrow ice-pick or boxcar scars, after which the surrounding skin is smoothed with TCA CROSS or laser resurfacing.

CO2 Laser

CO2 laser treatment resurfaces the skin more aggressively than Fraxel and is sometimes used in later sessions after TCA CROSS has already improved the depth of individual scars.

Erbium Laser

Erbium laser treatment offers another option for more aggressive resurfacing, often reserved for later sessions after TCA CROSS has softened the depth of individual scars.

Bellafill

Bellafill is a long-lasting filler often used to treat boxcar and rolling scars, adding volume beneath the scar to complement the surface improvement TCA CROSS provides.

Hyaluronic Acid Fillers (Restylane, Juvederm)

These fillers offer a temporary volumizing option for shallow rolling scars and can be used between TCA CROSS sessions to improve smoothness.

Dermal Fillers (Sculptra)

Sculptra works gradually to stimulate the body’s own collagen production over time, making it a good long-term complement to the more immediate resurfacing effects of TCA CROSS.

Laser Resurfacing

Laser resurfacing more broadly refers to treatments that remove damaged outer layers of skin to reveal smoother tissue underneath. It is often used to even out overall texture once individual scars have been treated.

Vbeam Laser

Vbeam laser treatment targets redness that can persist after scarring or TCA CROSS, helping skin tone appear more even.

IPL or Excel V

IPL and Excel V address pigment and vascular changes in the skin, making them useful additions for patients dealing with post-acne redness and textural scarring.

Chemical Peels

Chemical peels use a lower concentration of TCA or other acids across the broader face to exfoliate dull, discolored skin and smooth overall texture, complementing the more targeted improvement TCA CROSS provides for individual scar depressions.

Topical Retinoids

Topical retinoids support skin cell turnover and collagen production between in-office treatments, helping maintain and prolong the results of TCA CROSS and other procedures.

Because so many combinations are possible, Dr. Green tailors the pairing and sequencing of treatments to each patient’s scar type, skin tone, and healing response.

How many TCA CROSS treatments are needed, and how many sessions apart should they be spaced?

Most patients need three to four TCA CROSS sessions for optimal cosmetic results, though those with deeper acne scars may require more. Treatments are generally spaced six to eight weeks apart, and patients with darker skin tones or more significant scarring may need additional sessions. Dr. Green will build a personalized treatment plan that combines in-office procedures with specially formulated skincare products to help you achieve and maintain smooth, healthy skin.

It is best to wait 6 to 8 weeks between TCA CROSS sessions to allow the skin to heal, discoloration to resolve, and new collagen and elastin to remodel. Dr. Green evaluates your progress at each follow-up visit and often recommends a combination approach, layering TCA CROSS with treatments such as laser resurfacing, microneedling, or subcision with dermal fillers, depending on your specific scarring pattern.

What scar types does TCA CROSS work best on?

TCA CROSS is a safe and effective option for certain types of atrophic acne scars, namely ice pick and boxcar scars. Ice pick scars get their name from their deep, narrow shape, as though made by a sharp puncturing tool, while boxcar scars are rounder or oval-shaped with deep vertical sides and a wider appearance. A combination treatment approach is typically needed for the best results. When you consult with board-certified dermatologist Dr. Michele Green at her private practice on Manhattan’s Upper East Side, she will build a personalized acne scar treatment plan suited to your skin type, tone, and scarring pattern.

Frequently Asked Questions (FAQs) About TCA CROSS

Are the results of TCA CROSS permanent?

The cosmetic improvement achieved with TCA CROSS is permanent, though the treatment cannot prevent new signs of aging or the natural breakdown of collagen over time. Many patients choose to pursue additional skin rejuvenation treatments, such as laser resurfacing, microneedling, or dermal fillers, later to maintain their results. Dr. Green will work with you to develop a treatment timeline tailored to your ongoing skincare goals.

Is TCA CROSS painful?

TCA Cross is not painful. Each small amount of acid applied to a scar feels like a brief sting, and no topical numbing cream is necessary for the procedure.

What is the aftercare for TCA Cross?

Use SPF 50 or higher daily, wear hats, and avoid direct sun for the best cosmetic outcome. Apply emollients several times a day to support proper healing, and avoid overheating, strenuous exercise, hot tubs, saunas, steam rooms, and very hot showers for the first three days after treatment. You can resume regular skincare products once the skin returns to normal, and you should avoid picking, scrubbing, or exfoliating to prevent new scarring. Avoid electrolysis, waxing, or any hair removal in the treated area for at least two weeks.

What are the side effects of TCA Cross?

One of the most common potential side effects, especially in darker skin types, is post-inflammatory hyperpigmentation. Darker skin is more prone to this discoloration with higher-strength trichloroacetic acid solutions, though the darkening typically fades over several months. Many patients use a bleaching cream containing hydroquinone or Cosmelan starting about a week after treatment to help resolve this pigmentation. Strict sun avoidance remains essential throughout recovery. Other potential side effects include:

• Hypopigmentation, which is a possible side effect and may be permanent
• Erythema and local irritation from the procedure
• Increased acne scarring
• Infections
• Scarring
• Blisters
• Allergic reactions
• Peeling
• Acne breakout
• Activation of viral infections such as herpes simplex

What is the difference between a trichloroacetic acid peel (TCA peel) and TCA Cross?

TCA CROSS treats individual acne scars using a very high concentration of trichloroacetic acid (50-100%). In contrast, a TCA chemical peel uses a much lower concentration, typically 10-30%, and is applied across the entire face, chest, back, arms, or buttocks. TCA chemical peels address discoloration, sun damage, actinic keratoses, hyperpigmentation, fine lines, wrinkles, and acne breakouts, improving overall skin texture and tone, typically over a series of sessions. When you consult with board-certified dermatologist Dr. Michele Green at her private NYC dermatology office, she will evaluate your acne scars and recommend the combination of treatments that will most effectively smooth your skin.

Can I do TCA CROSS at home?

No. TCA CROSS uses a very high-concentration, medical-grade acid that only licensed physicians, such as Dr. Green, are trained to administer safely. Improper technique can cause hyperpigmentation, hypopigmentation, or scarring. For this reason, an experienced, board-certified dermatologist, such as Dr. Green in NYC, should always perform TCA CROSS and other acne scar treatments.

Can TCA CROSS make scars worse?

When performed by a board-certified dermatologist like Dr. Michele Green in NYC, TCA CROSS yields a smoother complexion and a visible reduction in acne scarring. Patients with a history of keloid scarring should avoid TCA CROSS, as the procedure can worsen skin texture rather than improve it. Incorrect technique in any patient can make scarring appear worse, which is why treatment with an experienced provider matters. In some cases, scars may look slightly worse before they improve as part of the natural healing process. Dr. Green closely monitors your progress throughout your TCA CROSS treatment to ensure you achieve smooth, healthy skin.

How long does it take to see results from TCA Cross?

Results from TCA CROSS can appear in as little as several weeks, though the timeline varies by patient. Some see significant improvement after the first session, while others need several sessions before noticing a difference. Dr. Green recommends waiting four weeks between treatments so progress can be reassessed at each visit. If no improvement is observed after the third session, she typically recommends switching treatment approaches.

How much does TCA Cross cost?

The total cost of TCA CROSS depends on several factors, including your provider’s experience, your geographic location, and the number of sessions needed to reach your goals. While treatment with a highly experienced, board-certified dermatologist such as Dr. Green may cost more, it is always worth choosing an expert, since acne scar treatments performed incorrectly or on the wrong skin type can cause complications such as hyperpigmentation or scarring. During your consultation at Dr. Green’s Upper East Side office, you will review your medical history and treatment goals together, and we can provide a personalized cost estimate at that time.

What TCA concentration is used for CROSS?

TCA CROSS uses a very high concentration of trichloroacetic acid, typically 50%-100%, applied only to the scar depression, not the surrounding skin. Lighter skin types can typically tolerate the full 100% concentration, while darker skin types usually receive a weaker 50% solution to reduce the risk of post-inflammatory hyperpigmentation. Dr. Green selects the precise concentration based on your skin type, tone, and the depth of each scar.

How deep does TCA penetrate?

Because TCA CROSS uses such a high acid concentration, it penetrates the epidermis. It reaches the deeper dermis, including the base of atrophic scar depressions, where it denatures damaged collagen and stimulates new collagen production. This depth of penetration allows TCA CROSS to remodel ice pick and boxcar scars from within, producing results that laser resurfacing or lighter chemical peels often cannot achieve on their own.

Is TCA Cross safe for darker skin tones?

TCA Cross is very difficult to perform on patients with skin type 3 or darker. It requires a more cautious approach because skin types 3 or darker are more prone to post-inflammatory hyperpigmentation and are generally not candidates for full-strength TCA CROSS. Dr. Green often uses a lower concentration in these patients, may recommend pre-treatment with skin-lightening creams, and typically prescribes hydroquinone before and after treatment to help prevent and manage discoloration. A thorough evaluation by a board-certified dermatologist experienced in treating darker skin tones, such as Dr. Green, is the safest way to determine candidacy.

What are signs of a bad TCA peel?

Warning signs of a poorly performed TCA peel or TCA CROSS treatment include uneven frosting, prolonged or spreading redness, unusually deep or widespread scabbing, blistering, and pigmentation changes that extend well beyond the treated scar. Persistent hyperpigmentation, new scarring, or hypopigmented patches that do not fade after several weeks can also indicate that the technique or acid concentration was inappropriate for the patient’s skin type. These outcomes are among the main reasons Dr. Green recommends that an experienced, board-certified dermatologist perform TCA CROSS only.

How to prepare for a TCA CROSS treatment

Preparing for TCA CROSS treatment begins several weeks before the appointment, as the skin needs to be in optimal condition to respond well to the acid and heal without complications. Patients are generally advised to stop using retinoids, exfoliating acids, and other active ingredients for about one week before treatment, as these can increase skin sensitivity and raise the risk of irritation. Minimize sun exposure in the weeks leading up to the procedure, and use broad-spectrum sunscreen daily (such as MGSkinLabs Hydrating SPF 50) to protect against pigment changes, since sun-damaged or actively tanned skin is more prone to post-inflammatory hyperpigmentation after acid application.

Additionally, patients taking isotretinoin must stop taking it at least six months before undergoing TCA Cross, because isotretinoin significantly impairs the skin’s healing capacity and increases the risk of scarring. Patients with active skin infections, cold sores, or open wounds in the treatment area should also postpone treatment until those conditions have fully resolved.

It’s also helpful to arrive at the appointment with a clean face, free of makeup and skincare products, and to expect some visible scabbing or discoloration over the treated pits in the days that follow. Consider scheduling around work or social commitments. During the consultation, Dr. Green evaluates the depth and pattern of the acne scars to determine the appropriate concentration of trichloroacetic acid and the number of sessions likely needed for optimal improvement.

Do you wash your face after a TCA CROSS?

Patients should avoid washing the treated area with harsh cleansers, hot water, or vigorous scrubbing in the days immediately after TCA CROSS, as the skin heals and scabs over the treated scars. Dr. Green will provide specific aftercare instructions, typically including gentle cleansing with lukewarm water, applying emollients to support healing, and waiting until the scabs resolve before resuming a normal skincare routine.

Which is better: CO2 fractional laser or TCA Cross?

Neither treatment is universally better, as each works differently and suits different types of acne scars. CO2 fractional laser resurfacing treats the skin’s surface more broadly, improving overall skin texture and tone and addressing mild-to-moderate atrophic scarring, but it typically involves more downtime. TCA CROSS, by contrast, targets individual deep ice pick and boxcar scars with pinpoint precision and often yields better results for these specific scar depressions than laser resurfacing alone. Many patients achieve the best outcome by combining both treatments, and Dr. Green will recommend the right approach based on your scar type and skin goals.

What is the downtime and recovery like for TCA CROSS?

Most patients experience approximately 7 days of downtime after TCA CROSS. Maintain strict skincare, use daily sunscreen, and protect your skin diligently during this period. Some patients notice mild redness or hyperpigmentation for a few weeks after treatment.

Schedule Your TCA CROSS Consultation with Dr. Michele Green in NYC Today

Acne scars can be a frustrating, lasting reminder of a past breakout, and treating them effectively requires an approach tailored to your skin type, skin tone, and the specific pattern of scarring you have, whether that involves ice pick, boxcar, or rolling scars, or a combination of these. TCA CROSS is one of the most effective options for reducing the appearance of atrophic acne scars. When combined with complementary treatments such as microneedling, subcision, or dermal fillers, it can produce smooth, lasting improvement in skin texture. Dr. Michele Green will evaluate your scarring in detail and build a customized treatment plan designed to help you achieve clear, healthy-looking skin.

Dr. Michele Green is an internationally renowned, board-certified dermatologist in New York City with over 25 years of experience, providing some of the world’s most discerning men and women with today’s best non-invasive rejuvenation treatments, including TCA CROSS, laser resurfacing, dermal fillers, Botox, and microneedling. Recognized for her dedication to her patients and clinical expertise, Dr. Green is consistently named among New York City’s top dermatologists by Castle Connolly, New York Magazine, and Super Doctors. To start your personalized TCA CROSS treatment plan, call Dr. Green’s office at 212-535-3088 or contact us online today.