Chemical Peels & Exfoliation

Exfoliation: Mechanical vs. Chemical

Exfoliation is the removal of dead cells from the stratum corneum, the outermost layer of the epidermis. It improves texture, brightens tone, unclogs pores, and helps products absorb. The exam splits exfoliation into two families.

• Mechanical (physical) exfoliation physically sloughs cells: granular scrubs, brushing machines, gommage, and microdermabrasion (a device that sprays crystals or uses diamond tips to abrade dead skin).
• Chemical exfoliation uses acids or enzymes to dissolve the desmosomes (the 'glue' holding dead cells together) so they shed. This includes AHAs, BHA, and enzyme peels that digest keratin.

The Texas Scope Limit (Critical Law)

Under TDLR scope of practice, a Texas esthetician may perform light/superficial peels that are non-invasive and non-aggressive and act only on the epidermis by removing dead cells. A peel that pierces or penetrates the dermis (living tissue) is a medical-grade procedure and is outside the esthetician license — it must be administered or delegated by a physician.

The same boundary applies to microdermabrasion: it is permitted only when it stays in the epidermis and does not reach the dermis. This depth limit is the single most testable peel concept on the Texas exam.

AHAs vs. BHA: Know the Difference

Glycolic acid is the most-used AHA because its small molecule penetrates fastest. Lactic acid is larger, gentler, and hydrating. Salicylic acid (the BHA) is oil-soluble, so it dives into sebum-filled pores — the go-to for acne and oily skin.

How Concentration and pH Control Depth

This is the chemistry trap. Two numbers determine how strong a peel is:

1. Concentration — the percentage of acid (e.g., 30% glycolic).
2. pH — the lower the pH, the more acid exists in its active free-acid form, and the deeper it works.

A 30% glycolic peel at pH 2.0 penetrates far deeper than the same 30% at pH 3.5, because lower pH unlocks more free acid. That is why a professional peel always lists both the percentage and the pH; concentration alone does not tell you the strength.

• Superficial AHA peels typically run 5–30%; superficial BHA peels typically 2–20%.
• After a peel, the skin is often neutralized with a basic (alkaline) solution to stop the acid's action when the protocol calls for it.

Step-by-Step Superficial Peel Procedure

1. Obtain written informed consent; review contraindications.
2. Cleanse and degrease the skin so the acid penetrates evenly.
3. Patch test if it is the client's first peel or a new product.
4. Apply the peel in even strokes; start the timer immediately.
5. Watch for endpoints — uniform light erythema (redness).
6. Neutralize/remove per the manufacturer's instructions.
7. Apply a soothing product and broad-spectrum SPF — post-peel skin is highly photosensitive.
8. Send home aftercare: no sun, no picking, no retinoids/scrubs for several days.

PPE, Consent, and Contraindications

During a peel, wear disposable gloves and eye protection if splashing is possible — the acid can irritate or burn your own skin and eyes. Informed consent is required because peels carry real risks (irritation, hyperpigmentation, scarring if misused) and the client must understand them before agreeing.

Absolute and relative contraindications to memorize:

• Isotretinoin (Accutane) within ~6 months — skin is too fragile.
• Active herpes simplex / cold sores — a peel can trigger a widespread outbreak.
• Pregnancy/nursing for certain acids (e.g., salicylic) — follow product guidance.
• Recent waxing, laser, microdermabrasion, or sunburn in the treatment area.
• Open lesions, active infection, or known allergy to the acid.

Common Exam Mistakes

The classic wrong answer is choosing a 'medium' or 'deep' peel for an esthetician — those reach the dermis and are out of scope. Another trap is assuming a higher percentage always means a stronger peel; pH matters just as much. Finally, skipping SPF aftercare is always wrong — peeled skin burns easily.

Specific Peel Solutions You Should Recognize

The exam may name common peel agents. Match each to its category and depth.

Note the last row: Jessner's solution (salicylic + lactic + resorcinol) and TCA (trichloroacetic acid) can reach the dermis and are medical procedures — refer these out.

Enzyme Peels and Fitzpatrick Considerations

Enzyme peels use fruit-derived proteolytic enzymes — papain (papaya) and bromelain (pineapple) — to digest the keratin holding dead cells. They are the gentlest chemical exfoliation and a safe choice for sensitive or first-time clients.

Use the Fitzpatrick scale (skin-typing I–VI by sun reaction and pigment) to gauge risk. Higher Fitzpatrick types (IV–VI) are more prone to post-inflammatory hyperpigmentation (PIH) after aggressive peels, so favor gentle acids (lactic, mandelic), lower strengths, and shorter contact times.

Reading the Skin's Reaction (Endpoints)

During a superficial peel you watch for an endpoint. Uniform light erythema (pinkness) is the typical superficial endpoint. Frosting (a white film from coagulated protein) signals deeper action beyond superficial scope — if you see it, neutralize immediately. Escalating sting, blanching, or gray patches mean stop and remove the product now.