Trichloroacetic Acid Peeling

Trichloroacetic acid peeling (TCA peeling) is a chemical peeling method (English to peel – abzuschälen), which is used as a cosmetic or dermatological procedure for the treatment of small impurities and wrinkles of the skin. The principle consists in the removal of dead skin scales from the top layer of the skin (epidermis) by the aggressive properties of trichloroacetic acid (C2HCl3O2; TCA). The procedure belongs to the “medium-depth peels”; it also reaches the dermis (leather skin). The effect of chemical peeling procedures is based on targeted damage to the skin to stimulate the regeneration mechanisms there. In the process, the stratum corneum (uppermost layer of the epidermis/skin) demonstrably becomes thinner, but also more compact. Furthermore, chemical peeling can contribute to the regulation of dysbiosis (imbalance of the skin flora) of the skin microbiome (totality of all microorganisms of the skin).PCA peeling also reaches the dermis (dermis) and can initiate dermal wound healing processes there by coagulation of proteins. This form of chemical peeling should be performed by a physician, as TCA is a keratolytic agent and can cause a relatively severe burn to the skin. The concentration of the acid determines the depth of penetration, which is classified as superficial, medium or deep (performed exclusively by a doctor!). Peeling is also used in combination with dermabrasion (abrasion of the skin) or laser skin resurfacing therapy (physical peeling).

Indications (areas of application)

  • Acneacne vulgaris, acne comedonica, acne excoriee.
  • Actinically damaged skin (light-damaged skin).
  • Actinic keratosis – change in the skin that occurs on light-damaged skin. It can be the precursor to squamous cell carcinoma of the skin, which is why it is considered a precancerous lesion (precancerous lesions; KIN (keratinocytic intraepidermal neoplasia)).
  • Chloasma (synonym: melasma) – circumscribed hyperpigmentation that occurs on the face and is hormonally caused.
  • Dyschromia (pigmentation disorders).
  • Wrinkles
  • Scars – especially acne scars
  • Hyperkeratoses – increased keratinization of the squamous epithelium of the skin.
  • Postinflammatory (after inflammation) hyperpigmentation or other pigmentary disorders.
  • Seborrheic keratosis (age warts).
  • Verrucae vulgaris (warts)

Contraindications

  • Active herpes simplex infection
  • Allergies – to exfoliating ingredients.
  • Bacterial or viral infections of the skin
  • Treatment with retinoids both externally and systemically – Do not peel until 12 months after systemic therapy, in the case of external treatment, discontinue the drug one week before.
  • Taking oral contraceptives (pill) or hormone therapy – increased risk of pigmentation disorders.
  • Fresh scars and wounds
  • Tendency to keloids (hypertrophic scarring)
  • Neoplasms (neoplasms) and tumors (skin cancer) of the skin.
  • Pathological inflammatory skin conditions – e.g. inflamed acne pustules.
  • Collagenoses (connective tissue diseases).
  • Photosensitivity (photosensitivity of the skin).
  • Radiatio/radiation therapy – in the area of the skin to be treated within the last six months.
  • Regular intake of steroids
  • Pregnancy
  • Very dark skin type
  • Teleangiectasia (dilation of small superficial skin vessels).
  • Previously performed(s)
    • Dermabrasion (mechanical peeling; abrasion of the skin).
    • Laser treatment of the skin (laser skin resurfacing; physical peeling).
    • Deep peeling
  • Wound healing disorders

Before treatment

At the beginning of a TCA peel, an informative patient interview and medical history is necessary to rule out any allergies or diseases (e.g., herpes simplex) that could compromise the treatment. For a medium-deep peel, a pre-treatment with a light superficial peel such as the fruit acid peel is suitable. Strong sun exposure should be avoided for at least two weeks before the peel appointment. The skin should be thoroughly cleansed and depilated before the procedure.Note: Prophylaxis of herpes reactivation in infected individuals (400 mg aciclovir three times daily starting 24 hours before peeling for six days until complete reepithelialization).

The procedure

Trichloroacetic acid peeling, as mentioned above, should be performed only by a physician, otherwise burns with permanent changes (scars, unsightly pigmentation) may occur. The depth of chemical peeling can be well controlled by the concentration of trichloroacetic acid:

  • Superficial peeling – 10-15% trichloroacetic acid causes superficial peeling of the epidermis (top layer of skin). This removes normal and actinically damaged (light damaged) keratinocytes (horny cells) and stimulates the renewal of the epidermis.
  • Medium to deep peeling – 15-25-(35)% trichloroacetic acid causes medium-deep peeling to the papillary dermis (dermis). However, side effects are more common here.

The TCA peel is applied to the skin to be treated in the desired dosage, depending on the selected penetration depth. Up to four layers are possible to achieve the effect. Since trichloroacetic acid penetrates well into the skin, priming (pre-treatment to dissolve the callus) is usually not necessary, although, as mentioned above, pre-treatment with low concentration fruit acid is sometimes used. Note: For facial peels, eye areas and lips should be protected from accidental contact with the peel solution by greasy externals (e.g., ointments, creams). The peel should not be used if there is acute inflammation or infection of the skin areas to be treated. If re-peeling is required, a grace period of at least 4 to 6 weeks should be observed.

After treatment

Following the peel, a dressing may be necessary. Greasy ointments or special wound and healing creams can support wound healing

Note: For medium-depth and deep peels, increased UV sensitivity will persist for several weeks. To avoid complicating healing, strong sun protection is very important. After a TCA peel, close follow-up is required in the days following treatment.

Possible complications

  • Swelling
  • Erythema (areal redness of the skin)
  • Hypopigmentation (loss of pigment)
  • Milia formation
  • Scars
  • Post-inflammatory hyperpigmentation; especially in people with darker skin type (skin type III-IV Fitzpatrick).
  • Pruritus (itching)
  • Visible demarcation lines (lines that indicate which part of the face has been treated and which has not).
  • Herpes simplex as well as bacterial infections.

Further notes

  • For a superficial chemical peel, winter is the appropriate season. Darker skin types (skin type III-IV Fitzpatrick) have low complication rates (3.8%) in such cases. In contrast, people with dark brown to black skin (skin type IV according to Fitzpatrick) have the most complications (12.5%).
  • Other substances used in chemical peeling are: 35-70% glycolic acid, 88% lactic acid, 40% mandelic acid and 10-30% salicylic acid, as well as combinations of these substances.

Benefits

Trichloroacetic acid peeling is a commonly used cosmetic method to improve the appearance of the skin. If performed properly by an experienced practitioner, it can improve the patient’s self-esteem and well-being.