14.1 Chemical Exfoliation & Peels

14.1 Chemical Exfoliation & Peels

Quick answer: Chemical exfoliation uses acids or enzymes to loosen dead surface cells. Superficial peels stay in the epidermis for cosmetic beautification; medium and deep medical peels go deeper and are not ordinary Massachusetts aesthetician work. Know AHA vs BHA mechanisms, how pH, percentage, and contact time change intensity, when to apply / neutralize / remove, post-peel SPF, and hard contraindications (isotretinoin, some acids in pregnancy, open wounds, recent waxing, active infection). Stay inside epidermal beautification under the Board of Registration of Cosmetology and Barbering.

On the PSI National Esthetician Theory exam used for Massachusetts aesthetician licensure, Advanced Treatments is a smaller domain by percentage (about 5%), but items are dense and safety-heavy. Writers expect you to sort cosmetic surface peels from medical-depth injury, match acid families to skin goals, and refuse a peel when history screams “not today.” Product chemistry (Chapter 10) already introduced pH and acid mantle ideas; this section applies those ideas to professional peel judgment.

Superficial Peels vs Deeper (Medical) Peels

Not every service labeled “peel” is the same legal or clinical act.

Exam language cue: Words like frosting expected, phenol, medical-grade TCA medium peel, dermal resurfacing, ablative medical peel point away from ordinary aesthetician practice. Words like superficial glycolic facial peel, enzyme polish, low-strength lactic brightening step can fit cosmetic epidermal work when training, product, and skin allow.

Massachusetts candidates should recite a scope sentence on every peel stem: I may perform beautification that remains epidermal; I do not diagnose disease or create medical-depth injury because a client paid for a package or works in a med spa. The May 2025 Board policy theme still applies here—employment in a medical spa does not expand aesthetician scope. A physician’s hallway nearby is not a medium-depth peel license.

AHA and BHA Mechanisms (Exam Core)

Alpha-Hydroxy Acids (AHAs)

AHAs (common teaching examples: glycolic, lactic, mandelic, citric in some formulations) are water-soluble acids. They work primarily by weakening corneocyte cohesion in the stratum corneum so dead cells release more evenly. Clinical teaching goals often include smoother texture, improved radiance, and support for fine surface dullness when used correctly.

Beta-Hydroxy Acid (BHA) — Salicylic

Salicylic acid is the classic BHA in esthetics theory. It is oil-soluble (lipophilic), so it can travel into oily environments and is frequently associated with congested, oily, and acne-prone surface concerns. It also has keratolytic teaching properties and mild antiseptic associations in classic texts.

Enzyme exfoliants (papain, bromelain teaching examples) digest keratin proteins and often appear as milder or alternative chemical routes for sensitive or reactive clients—still require analysis and timing, still are not “harmless fruit snacks.”

pH and Percentage Concepts at Exam Level

Professional peel intensity is not “the higher the number on the jar, the better the glow.” Exam-level variables include:

1. Acid type (glycolic ≠ salicylic ≠ enzyme).
2. Percentage / concentration of acid in the formula.
3. pH of the finished product (lower pH often increases potential activity for many acid systems in teaching models).
4. Free acid availability and vehicle (formulas are not simple kitchen dilutions).
5. Layers applied and contact time.
6. Skin condition today (barrier status, inflammation, Fitzpatrick-related PIH risk, medications).

Teaching point from chemistry: Each full pH unit is a tenfold hydrogen-ion change in simplified scale teaching. A peel at a much lower pH is not “a little stronger”—it can be dramatically more aggressive. Pair that with percentage, and you understand why two products both labeled “glycolic” can behave very differently.

Application Timing: Apply, Neutralize, Remove

A professional peel is a controlled process, not a leave-on toner used carelessly.

Typical exam-safe workflow concepts:

1. Consultation / intake review — isotretinoin, retinoids, recent peels/lasers/waxing, pregnancy/nursing, cold sores, allergies, keloid/PIH history, current inflammation.
2. Cleanse and assess — no product on dirty skin; confirm integrity of the barrier.
3. Protect eyes, lips, and sensitive borders as trained; drape and ventilate per product SDS/directions.
4. Apply evenly with appropriate applicators; avoid pooling in nasolabial folds and eye orbits.
5. Time the contact exactly as directed.
6. Neutralize and/or remove per manufacturer:
   • Some systems require a dedicated neutralizer.
   • Others are removed with water or a specific remover.
   • Do not invent a neutralization step that the product forbids—or skip one the product requires.
7. Assess endpoint — even color, expected mild erythema within protocol; stop early for frosting, blanching, or distress outside expected parameters for that product class (and escalate/refer when injury exceeds cosmetic response).
8. Calm, hydrate, protect — finish with appropriate barrier support and SPF counseling (daytime essential).

Timing is not pain-based. “It doesn’t sting, so leave it longer” and “it burns, so it must be working—add another layer” are both failure modes. Manufacturer contact time and visual/protocol endpoints control the service.

Post-Peel Care and SPF

After chemical exfoliation, the stratum corneum is thinner and more vulnerable. Client education is part of the treatment, not an optional brochure:

• Broad-spectrum SPF daily (and reapplication habits) — primary non-negotiable message.
• Avoid picking, aggressive scrubs, waxing, and stacked acids/retinoids during the recovery window the protocol defines.
• Prefer gentle cleansing, humectant + emollient support, and products that do not strip.
• Expect possible flaking, tightness, or pinkness within expected ranges; unexpected blistering, severe pain, or infection signs → stop home self-treatment advice and refer medically.
• PIH risk rises with trauma + UV, especially in medium-to-deeper Fitzpatrick phototypes—counsel honestly; under-treat rather than over-injure.

Contraindications and Red Flags (High-Yield)

Refuse or postpone chemical peels (or heavily modify to the mildest allowed protocol) when history or analysis shows elevated risk:

Isotretinoin stems are favorites. Correct answers pause aggressive chemical exfoliation and mechanical trauma; wrong answers “proceed carefully with gloves” as if gloves fix dermal fragility.

Massachusetts Scope: Epidermal Beautification Only

Tie every peel decision back to Board limits:

• You provide cosmetic, epidermal-level chemical exfoliation within training and product rules.
• You do not diagnose acne vulgaris grades as a physician would, prescribe oral meds, or perform medical-depth peels because a med spa menu uses medical words.
• You do consult, analyze, patch-test when appropriate, document, and refer when presentation is medical.
• Advanced popularity on social media does not rewrite 240 CMR or Board outside-of-scope policy.

Worked Exam Scenario

A client wants a “medical TCA medium peel” at a Boston med spa. Intake shows she finished isotretinoin four months ago (confirm your school’s absolute timing rules; many protocols still restrict aggressive resurfacing), has a history of PIH, and was waxed on the face yesterday. She says the medical director “doesn’t mind if aestheticians do what nurses do.”

Correct path: decline medical-depth TCA, decline stacking peel on freshly waxed skin, respect isotretinoin-related fragility windows, explain May 2025-style scope (workplace does not expand license), offer only what is epidermal, indicated, and timed safely—or reschedule and refer. Incorrect path: apply a strong multi-layer acid “because she signed a waiver.”

How This Shows Up on MA PSI Theory

Expect stems on:

• Superficial vs medical peel depth
• AHA water-soluble vs BHA oil-soluble mechanisms
• Why pH/percentage/time matter together
• Neutralize/remove per manufacturer
• SPF aftercare
• Isotretinoin, pregnancy acid cautions, open wounds, recent waxing, active infection
• Scope refusal inside a med spa story

Common Traps

• Equating all “peels” with one legal permission level
• Using pain as the timer
• Skipping SPF counseling
• Peeling over waxed or broken skin
• Assuming med spa employment authorizes medium/deep medical peels
• Stacking scrub + strong peel + extractions on a fragile barrier in one visit

Study Routine

• Two-column card: AHA vs BHA (solubility, classic use case, one caution)
• Depth table: superficial vs medium/deep + who performs
• Contraindication list recited out loud in 30 seconds
• Verbal script: “Epidermal beautification only; manufacturer time; SPF tonight and every day”

Final Check

Without notes, define superficial vs medical-depth peels; contrast AHA and BHA; list five intensity variables; describe apply → time → neutralize/remove → SPF; name five contraindications including isotretinoin and recent waxing; and state that MA aestheticians remain inside epidermal beautification. Clean recall means you are ready for microdermabrasion rules in Section 14.2.