Aesthetic Dermatology MCQ - Peeling Side effects

A 50-year-old woman with Fitzpatrick skin type III undergoes a medium-depth 35% trichloroacetic acid (TCA) peel for moderate photodamage. Two weeks post-procedure, she presents with persistent erythema and early, firm, raised scars in the mandibular area. Which of the following is the most likely complication and the most critical next step in management?

A) Hypertrophic scarring; initiate intralesional triamcinolone
B) Postinflammatory hyperpigmentation; begin hydroquinone 4%
C) Infection; start oral antibiotics
D) Allergic contact dermatitis; apply topical corticosteroids
E) Milia formation; perform manual extraction

Correct Answer: A) Hypertrophic scarring; initiate intralesional triamcinolone

Explanation

This question addresses a serious complication of chemical peels, particularly medium-depth peels like TCA 35%.

Why This is Hypertrophic Scarring:

• Timing: The presentation 2 weeks post-peel with persistent erythema and firm, raised scars is classic for early hypertrophic scarring.

• Risk Factors: The mandibular area is a high-risk zone for scarring due to reduced pilosebaceous units and slower healing. Other risk factors include aggressive peeling technique, poor postoperative care, or inherent patient susceptibility (e.g., history of keloids).

• Pathophysiology: Overaggressive wounding leads to excessive collagen deposition during healing.

Why Intralesional Triamcinolone is Critical:

• First-Line Treatment: Intralesional triamcinolone acetonide (e.g., 10-20 mg/mL) is the gold standard for managing hypertrophic scars. It suppresses collagen synthesis, inflammation, and fibroblast proliferation.

• Administration: Injected directly into the scar every 4-6 weeks.

• Goal: Reduce scar volume, erythema, and pruritus while preventing progression.

Why Not the Other Options?

• (B) Postinflammatory hyperpigmentation (PIH): Would present as brown macules/patches, not raised scars. PIH is common after peels in darker skin types but is managed with hydroquinone, retinoids, and sun protection.

• (C) Infection: Would present with pustules, purulent discharge, pain, or systemic symptoms (e.g., fever), not typically with firm, raised scars so early.

• (D) Allergic contact dermatitis: Would cause pruritic, eczematous plaques, often with vesicles, not firm scars. It is rare with TCA peels.

• (E) Milia formation: Appears as small, white, superficial cysts weeks to months post-peel due to occluded pilosebaceous units. It is not raised or firm like a scar and is managed with extraction or retinoids.

Prevention and Management of Peel Complications:

• Preoperative: Assess risk factors (skin type, history of scarring), test peel in a small area, and prime skin with retinoids.

• Intraoperative: Apply peel evenly and avoid over-frosting.

• Postoperative: Use gentle wound care, strict sun protection, and monitor for prolonged erythema (>2 weeks), which is a red flag for scarring.

Prognosis:
With prompt intervention, hypertrophic scarring can be controlled. Delay in treatment may lead to permanent scarring.

Note: Persistent erythema beyond 2 weeks after a medium or deep peel is a warning sign of impending scarring and requires immediate intervention. Intralesional corticosteroids are first-line, and pulsed dye laser can be added for erythema. Always rule out infection if there is doubt.