Skin barrier cross-section Cross-section of the skin on a caregiver's hand: skin cells (bricks) sealed by lipid mortar. Gloves, soap and water at every door strip the mortar, moisture escapes and irritants get in. SURFACE · BACK OF THE HAND · ROOM TO ROOM PHASE 1 · HEALTHY CROSS-SECTION, NOT TO SCALE Stratum corneum 10–20 layers of flat, dead cells.Your outer barrier. Lipid “mortar” Ceramides, cholesterol, fatty acidsseal the gaps between the bricks. Living epidermis Makes new cells that move up andflatten over about 4 weeks. Dermis Collagen and blood vessels. LEGEND Water Irritants Glove Soap and water

Brick-and-mortar model of the stratum corneum: Elias PM, J Invest Dermatol 1983;80:44s–49s. Exposure: R&R Lotion blog, Understanding Occupational Dermatitis and I.C. Hand Lotions (2023). Illustration for education only.