TCA Cross

How does TCA CROSS work?

Atrophic acne scars develop when inflammation damages the skin’s deeper supportive tissue and the area does not produce enough collagen during healing. This leaves a visible depression in the skin.

During TCA CROSS, concentrated acid is carefully placed along the base and walls of the scar. The treated area briefly turns white, a response known as frosting. This controlled injury activates the skin’s repair process and stimulates collagen remodeling.

Improvement develops gradually over several months as the scar rebuilds from within. TCA CROSS can make scars shallower and less noticeable, but it is unlikely to remove them completely.

What types of acne scars can TCA CROSS treat?

TCA CROSS is most commonly used for:

• Deep ice-pick scars
• Narrow boxcar scars
• Selected enlarged pores
• Other small, sharply defined atrophic scars

Ice-pick scars are narrow openings that extend deeply into the skin. Boxcar scars are wider depressions with more clearly defined edges. These scar types often respond well because the acid can be placed directly inside the depression.

Some rolling scars may be treated, but TCA CROSS is generally less effective when the scar is broad or tethered beneath the skin. Rolling scars may respond better to subcision, microneedling, fractional laser treatment or a combination of procedures.

Why is an acne-scar evaluation important?

Most patients have more than one type of acne scar. Ice-pick, boxcar and rolling scars can appear together, but each type responds differently to treatment.

Your provider will examine the depth, shape, distribution and severity of your scars before recommending a plan. Active acne should also be addressed because continued breakouts can create new scars while existing scars are being treated.

A personalized combination of treatments often produces better overall improvement than relying on one procedure alone.

What areas can be treated?

TCA CROSS is used primarily for acne scars on the face, including the:

• Forehead
• Temples
• Cheeks
• Nose
• Chin
• Jawline

Selected scars elsewhere on the body may also be considered. Treatment concentration and technique may need to be adjusted because skin thickness, healing and the risk of discoloration vary by location.

What happens during treatment?

Your appointment begins with an examination of your scars and a review of your medical history, medications, skin-care products and previous procedures.

The skin is thoroughly cleansed. Your provider then uses a fine applicator to place a very small amount of TCA precisely inside each selected scar. The acid is confined to the scar whenever possible to protect the surrounding skin.

The treated scar will briefly develop a white, frosted appearance. After all selected scars have been treated, appropriate skin-care products and sunscreen may be applied.

The procedure generally takes 30 minutes or less, depending on the number of scars being addressed.

Is TCA CROSS uncomfortable?

Most patients experience brief stinging, warmth or burning as each scar is treated. Because the acid is applied to very small areas, the discomfort is generally short-lived.

The sensation may vary depending on the number, depth and location of the scars. Tell your provider immediately if you experience severe or unexpected pain during treatment.

How many treatments will I need?

TCA CROSS is generally performed as a series rather than a one-time treatment. The Dermatology Clinic typically recommends approximately three to six sessions spaced six to eight weeks apart.

The number of treatments needed depends on:

• The type and depth of the scars
• The number of scars being treated
• The concentration and technique used
• Your natural skin tone
• Your healing response
• Previous scar treatments
• Your desired level of improvement

Multiple treatments generally produce greater improvement than a single session, but results vary and complete scar removal should not be expected.

When will I see results?

TCA CROSS results develop gradually. Some improvement may become noticeable approximately six to eight weeks after treatment, but collagen remodeling can continue for several months.

The scars may temporarily look deeper, darker, wider or more noticeable during the early healing process. This does not necessarily represent the final result.

Improvement typically becomes easier to evaluate after the crusts, redness and temporary discoloration have resolved. Additional changes may develop as the treatment series progresses.

What results can I expect?

TCA CROSS may make appropriately selected scars:

• Shallower
• Less sharply defined
• Less noticeable in certain lighting
• Easier to improve with additional scar treatments
• More even with the surrounding skin

The procedure cannot guarantee completely smooth skin or erase every scar. Results depend on scar type, depth, treatment precision, number of sessions and individual healing.

Although the collagen produced during treatment can provide lasting structural improvement, the skin will continue to change with aging, acne, sun exposure and other environmental factors.

What happens immediately after treatment?

The treated scars will turn white or frosted immediately after the acid is applied. This frosting may remain visible for several hours and can occasionally last up to approximately 12 hours.

Redness commonly develops around the treated areas. Over the following two to three days, each spot may darken and form a small crust or scab.

The crusts typically separate naturally within approximately three to seven days. Pinkness or redness may remain after the crusts fall away and can last longer in some patients.

Is there any downtime?

TCA CROSS creates visible pinpoint areas of healing. Most patients can continue their regular daily activities, but the treated scars may remain noticeable for approximately one week or longer.

Temporary effects may include:

• White frosting
• Redness
• Stinging or tenderness
• Small dark crusts or scabs
• Dryness or itching
• Temporary darkening of the treated areas
• Prolonged pinkness
• Temporary lightening or darkening of the skin

Makeup may be used after the skin is intact and your provider says it can be applied safely. Do not apply makeup over open or actively weeping areas.

How should I prepare for treatment?

Before your TCA CROSS appointment:

• Avoid tanning and excessive sun exposure for two to four weeks
• Use broad-spectrum sunscreen consistently
• Avoid self-tanning products on the treatment area
• Follow instructions regarding retinoids, alpha hydroxy acids, beta hydroxy acids and other exfoliating products
• Tell your provider about all prescription and over-the-counter skin products
• Report any medication that affects healing or increases skin sensitivity
• Discuss recent chemical peels, lasers, microneedling, injectables or other procedures
• Tell your provider if you have used or recently stopped isotretinoin
• Report a history of cold sores, poor wound healing, keloids or abnormal scarring
• Report any active acne, rash, infection, sunburn, open wound or irritation
• Arrive with clean skin and no makeup when possible

Patients prone to post-inflammatory hyperpigmentation may be given a pretreatment skin-care plan that includes pigment-regulating products. Use these products only as directed by your provider.

How should I care for my skin afterward?

Follow the personalized instructions provided by your treatment team.

After TCA CROSS:

• Cleanse the skin gently
• Apply petrolatum or another approved healing ointment as directed
• Do not pick, scratch, peel or remove the crusts
• Avoid retinoids, exfoliating acids, scrubs and harsh products
• Avoid facial brushes and cleansing devices
• Limit direct sun exposure
• Apply broad-spectrum sunscreen with an SPF of 30 or higher
• Avoid tanning
• Avoid excessive heat and sweating while the areas are healing
• Allow all crusting and flaking to separate naturally

Picking at the treated skin can increase the risk of infection, discoloration, scar enlargement and permanent scarring.

Why is sun protection important?

Sun exposure during healing can make redness last longer and increase the risk of post-inflammatory hyperpigmentation.

Use broad-spectrum sunscreen every day and reapply it when outdoors. A wide-brimmed hat and physical shade provide additional protection.

Sun protection remains important after healing because ultraviolet exposure can worsen discoloration, damage collagen and make textural irregularities more noticeable.

Can TCA CROSS be used on different skin tones?

TCA CROSS has been studied in a range of skin tones, but any controlled skin injury can cause post-inflammatory hyperpigmentation or, less commonly, loss of pigment.

Patients with melanin-rich skin may require:

• Careful scar and skin assessment
• Conservative treatment settings
• Pretreatment with pigment-regulating products
• Strict sun protection
• Longer intervals between sessions
• Close monitoring during recovery

Treatment should be performed by a provider experienced in chemical scar reconstruction and pigmentation management. TCA CROSS should not be described as risk-free for any skin tone.

What are the possible risks?

TCA CROSS is generally well tolerated when performed precisely on an appropriate candidate, but complications are possible.

Potential risks include:

• Prolonged redness or irritation
• Post-inflammatory hyperpigmentation
• Temporary or permanent hypopigmentation
• Infection
• Delayed healing
• Persistent crusting
• Scar enlargement
• Worsening of scar depth
• Two nearby scars joining into one larger depression
• Changes in skin texture
• Permanent scarring
• Limited or uneven improvement

Allowing the acid to spread outside the intended scar can damage surrounding skin and worsen the scar. Precise application by an experienced provider is essential.

What symptoms should be reported?

Contact the clinic if you experience:

• Increasing or severe pain
• Significant swelling
• Blistering
• Pus or drainage
• Spreading redness or warmth
• Fever
• An open sore that is not healing
• Pale, gray, blue or unusually dark skin
• A cold-sore outbreak
• Crusting that becomes progressively worse
• Another unexpected or worsening reaction

Do not attempt to treat a significant reaction with additional acids, exfoliants, bleaching products or unapproved medications.

Who is a good candidate for TCA CROSS?

TCA CROSS may be appropriate for patients with mature, sharply defined atrophic acne scars, particularly ice-pick and narrow boxcar scars.

Good candidates generally:

• Have healthy, intact skin
• Have controlled or inactive acne
• Have scars appropriate for focal acid application
• Have realistic expectations
• Understand that several treatments may be needed
• Can avoid picking the healing skin
• Can follow strict sun-protection and aftercare instructions

A consultation is necessary because not every depressed scar will respond to TCA CROSS.

Who may need to postpone treatment?

Treatment may need to be postponed or avoided if you:

• Have actively tanned or sunburned skin
• Have active inflammatory or cystic acne in the treatment area
• Have a bacterial, viral or fungal skin infection
• Have an active cold sore
• Have an open wound or irritated skin
• Have a history of poor or delayed wound healing
• Have a history of abnormal or keloid scarring
• Have uncontrolled diabetes or another condition that affects healing
• Have recently undergone another procedure that has not healed
• Are taking medication that interferes with healing
• Have active vitiligo or a history of inflammation-triggered pigment loss
• Are pregnant or breastfeeding

Provide a complete medical, medication and treatment history so your provider can determine whether the procedure can be performed safely.

Can TCA CROSS be combined with other treatments?

Acne scars often require more than one type of treatment. Depending on your scar pattern, TCA CROSS may be combined with:

• Microneedling
• Radiofrequency microneedling
• Fractional laser resurfacing
• Subcision
• Dermal fillers
• Chemical peels
• Other scar-revision procedures

TCA CROSS is often selected for deep ice-pick scars, while another procedure is used for broader boxcar scars, rolling scars, discoloration or overall texture.

Some treatments may be performed during the same treatment period, while others should be spaced apart to avoid excessive inflammation and allow proper healing. Your provider will recommend the safest sequence.

What makes TCA CROSS different?

Traditional chemical peels spread an exfoliating solution across a larger section of skin. TCA CROSS uses concentrated acid only inside selected scars.

This focal approach allows deeper scars to be treated without intentionally peeling the entire surrounding area. The technique is especially useful for narrow scars that may be difficult to improve with surface-level treatments alone.

Because concentrated acid is used, the procedure requires precise placement and should not be attempted at home.

Schedule a TCA CROSS consultation

TCA CROSS offers a targeted approach to improving deep ice-pick and selected boxcar acne scars by stimulating collagen within each individual depression. The Dermatology Clinic can evaluate your scar types, determine whether TCA CROSS is appropriate and create a personalized plan that may include additional treatments for more comprehensive improvement. Contact us today to get scheduled.