Before I green‑light acids, I do a quick barrier check: TEWL <12 g/m²/h on the malar cheek and corneometer hydration >35 AU; if either is off, I pivot to LED (633/830 nm at about 60 mW/cm² for 10 minutes) and lipid repair for 14 days… This has halved post‑peel PIH in Fitz IV–VI in my clinic — what thresholds or devices are you using at consult?
I get fewer false highs on TEWL by letting clients acclimate 10 minutes at about 45–50% RH before the malar reading; otherwise I see +2–3 g/m²/h that would trip your <12 cutoff. If TEWL is 12–14, I do a cool saline wipe and recheck in 2 minutes — if it normalizes, I proceed; if not, I switch to your LED ‘633/830 nm for 10 minutes’. @OP, which corneometer are you using — my Courage+Khazaka CM 825 reads about 3 AU higher right after cleanse.