Advanced Treatments: Exfoliation and Chemical Peels
Advanced Treatments: Exfoliation and Chemical Peels
This domain tests exfoliation methods, peel chemistry, pH and free-acid concepts, neutralization, contraindications, and complication management.
Core rules
- AHAs such as glycolic and lactic acid are water-soluble; BHAs such as salicylic acid are lipid-soluble and more follicular.
- Peel strength depends on acid type, concentration, pH, free-acid value, contact time, and skin prep. Lower pH generally increases free acid and penetration.
- AHAs are often neutralized; TCA and some peels are self-neutralizing. Follow the manufacturer's protocol exactly.
- Contraindications include pregnancy for certain acids, isotretinoin use, active infection, recent laser, waxing, sunburn, and impaired barrier.
- Post-peel care includes gentle cleansing, barrier repair, and strict SPF. Warn about frosting, redness, and delayed pigmentation.
Worked example
A 20% salicylic peel at pH 3 and a 30% glycolic peel at pH 2.5 are proposed. Compare concentration, pH, lipid solubility, and expected depth rather than assuming the higher percentage is stronger. Salicylic acid is lipophilic and may target pores; glycolic acid is an AHA with different penetration. Reasoning: percentage alone does not determine potency; pH and free acid matter.
Traps
- 'Higher percentage always means a stronger peel' is false.
- Not every peel uses a neutralizer.
- Skipping SPF increases post-inflammatory hyperpigmentation risk.
- Treating recently waxed or irritated skin raises complication risk.