Aesthetic Dermatology MCQ - Medium-Depth Chemical Peels

A 48-year-old woman with mottled pigmentation, multiple actinic keratoses, and fine perioral rhytides wishes for a single-session procedure to improve her skin texture. You decide to perform a peel that reaches the papillary dermis. Which of the following combinations is MOST characteristic of a medium-depth chemical peel?

A. Glycolic acid 20–50% applied every 2 weeks
B. Phenol (Baker-Gordon formula) peel
C. 35% Trichloroacetic acid (TCA) alone or combined with Jessner’s solution
D. Salicylic acid 30% peel
E. Croton oil peel

Correct Answer:
C. 35% Trichloroacetic acid (TCA) alone or combined with Jessner’s solution

Explanation:
Medium-depth peels penetrate the epidermis and papillary dermis, producing epidermolysis and necrosis of the upper dermis. They are used to treat:

• Actinic keratoses

• Solar lentigines

• Epidermal melanosis (e.g., melasma)

• Fine wrinkles and mild acne scarring

Common agents/combinations for medium-depth peels:

• 35% TCA (alone)

• Jessner’s solution + 35% TCA (enhances penetration)

• Glycolic acid 70% + 35% TCA

• Solid CO₂ + 35% TCA (classic combination)

Other options:

• A. Glycolic acid 20–50%: Superficial peel (epidermal).

• B. Phenol (Baker-Gordon): Deep peel (reticular dermis).

• D. Salicylic acid 30%: Superficial metabolic peel (sebostatic).

• E. Croton oil peel: Deep phenol-based peel used for severe photodamage.

Key Point:
Medium-depth peels (TCA 35%) are ideal for actinic damage and dyschromias, producing a controlled wounding up to the papillary dermis. They require longer downtime than superficial peels but have fewer systemic risks than phenol deep peels.