A wall of bricks and mortar
The top layer of skin is built like a wall: cells are the bricks, and the lipids between them are the mortar. This wall keeps water in and irritants out. While it is intact, skin looks calm, smooth and 'low-maintenance'.
Breach it — and water evaporates, irritants get in, and the skin starts to 'talk': tightness, flaking, stinging from products you have 'always used', redness without an obvious cause.
How we destroy it (with the best of intentions)
The consulting-room chart: aggressive cleansing and 'squeaky cleanliness'; daily acids and retinoids without adaptation; hot water; exfoliating already-irritated skin; and a collection of ten actives fighting each other.
The irony is that the more irritated the skin gets, the more products we buy — and the more we irritate it. That circle is the first thing we break, before any treatment.
The signs your barrier is breached
Everything stings — even water. The skin is oily and flaky at the same time. It feels tight after washing. Familiar products suddenly 'stop working'. Make-up sits in patches. If you recognise three out of five — keep reading.
Repair: boring and effective
The regimen is almost disappointingly simple: gentle cleansing once or twice a day, a generous emollient with ceramides or similar lipids, sunscreen in the morning — and nothing else for 2–4 weeks. No acids, no retinoids, no peels, no new products.
Skin renews itself in about a month — give it that month. Then actives return one by one, onto a healthy foundation. With eczema, dermatitis or rosacea, barrier repair runs alongside treatment — that is decided at an examination.
My closing rule
When skin is irritated, instinct says 'do more'. Dermatology says: do less, but do it right. If you are not sure where to start — that is what consultations are for. Repairing a barrier is easier than it sounds; the hard part is to stop getting in its way.