Moist Wound Healing

Moist wound healing is the practice of keeping a superficial wound covered and hydrated rather than letting it dry into a scab. George Winter's 1962 experiment on porcine skin found that wounds covered with a polythene film re-epithelialized roughly twice as fast as identical wounds left open to air. A scab is not a scaffold; it is desiccated tissue that migrating keratinocytes have to tunnel beneath. Remove the barrier to migration and the cells cross sooner.

The folk instruction to "let it breathe" is a good example of a rationale that sounds mechanistic and is not — oxygen for epithelial migration comes through the perfused wound bed, not the air above it. The intuition earns its persistence from the visible crust looking like progress, which makes it a case study in Plausible Mechanism.

Practical technique. Irrigate with clean water or saline at adequate volume to remove debris; antiseptics in the wound bed are cytotoxic to the same cells being asked to migrate. Choose a dressing by exudate: transparent films for dry or lightly weeping wounds, hydrocolloids and foams for moderate exudate, alginates for heavy. Do not mistake the gel that forms under a hydrocolloid for pus.

Traumatic tattooing is the permanent pigmentation left when grit, asphalt or carbon is not removed from an abrasion before it epithelializes. Once the surface closes over the particulate, the marking is effectively permanent, so thorough early scrubbing matters — a procedure painful enough that local anaesthesia or a Regional Nerve Block is often warranted given the Nociception involved. Healing capacity ultimately follows perfusion, as Watershed Blood Supply describes.