Chemical Exfoliation and Peel Application
Depth classification
Superficial peels act on the stratum corneum through the epidermis. Medium peels reach the papillary to upper reticular dermis and typically produce visible sloughing. Deep peels reach the reticular dermis and are medical procedures outside esthetic scope. Depth is a product of the agent, its concentration and pH, the number of layers, contact time, skin temperature, degreasing and prep, occlusion, and the client's own barrier and Fitzpatrick type.
Agents and neutralization
Glycolic and lactic acids are water-soluble AHAs and are neutralized or thoroughly removed. Salicylic acid is lipid-soluble, self-limiting as it crystallizes, and is generally avoided in pregnancy. Mandelic acid is larger and slower. TCA is self-neutralizing and produces predictable frosting that clears in minutes. Jessner solution is typically self-neutralizing. Resorcinol and phenol carry systemic toxicity concerns and belong to physicians.
Safety architecture
History and contraindication screen, patch test where indicated, informed consent, eye protection, degreasing, timed application, vigilant monitoring, neutralization, post-care with barrier repair and SPF, and written aftercare instructions. Absolute or strong contraindications include isotretinoin use, pregnancy and breastfeeding for many agents, active infection, open lesions, recent waxing, laser, or dermabrasion, photosensitizing medications, compromised immunity, and a keloid history in the treatment area.
Complications
Prolonged erythema, blistering, PIH, hypopigmentation, herpes reactivation, and infection. Frosting that is gray, dense, or persistent is a stop signal, not an endpoint to reach.
Traps
- Assuming TCA needs a neutralizer.
- Treating a tanned client because the tan looks light.
- Continuing because the timer says so when the skin already shows an endpoint.
Rule of thumb
Plan the peel in advance, but deliver the peel to the skin in front of you. When in doubt, use fewer layers and less time.