Delayed Re-epithelialization Following Full-Field Er:YAG Laser Resurfacing: A Case Report

Full-field erbium-doped yttrium aluminum garnet (Er:YAG) laser resurfacing is widely used for photoaging and scars, with re-epithelialization expected within five to seven days. Delayed healing is uncommon and may result from infection, inappropriate wound care, or allergic contact dermatitis (ACD). We present a 32-year-old woman who underwent full-face Er:YAG resurfacing (fluence: 8 J/cm², pulse duration: 300 µs, four passes, depth: 600 µm). Despite standard postoperative instructions, she substituted petrolatum ointment with a lanolin-containing moisturizer. At day seven, erosions and crusting persisted. Cultures and potassium hydroxide preparations were negative. Patch testing with the European Baseline Series and supplementary wound-care allergens (total: 45) demonstrated a strong positive reaction to lanolin (wool alcohols, 30% petrolatum), confirming ACD. Treatment included discontinuing the lanolin-containing product, substituting with plain petrolatum, initiating clobetasol propionate ointment, and prescribing a seven-day course of oral prednisone (30 mg daily). Rapid improvement followed, with complete epithelialization by day 21 and no scarring or pigment alteration. This case demonstrates lanolin-induced ACD as a cause of delayed epithelialization after laser resurfacing. Although negative microbiological studies cannot exclude infection, the strong positive patch test confirmed lanolin as the causative agent. Reporting of laser settings, diagnostic limitations, and wound care regimens is critical in case reports to enable reproducibility and contextual understanding. Patient education and careful postoperative product selection are vital to avoid preventable complications. Lanolin allergy should be considered in cases of delayed wound healing after ablative resurfacing. Early patch testing and substitution with inert, lanolin-free petrolatum can accelerate recovery. Clinicians must emphasize evidence-based wound care, avoidance of sensitizers, and prompt evaluation when healing deviates from the expected course.