Foam dressing is a type of bandage that provides the protection and airflow necessary to speed wound healing. The porous foam surface of the bandaging material creates a moist environment that allows the body to heal itself naturally. 

What are foam dressings?

Foam dressings are designed to meet one of the main goals of wound care: creating a moist environment conducive to wound healing. They’re generally made from semipermeable polyurethane, so they’re nonadherent and nonlinting and the dressings allow water vapor to enter but keep out bacteria and other contaminants. The outer layer may be waterproof or hydrophobic. Foam dressings are available in various sizes and shapes. Some have adhesive tape, or boaders, around the edges for easier application.

When should I use foam dressings?

A variety of wound types with at least a moderate amount of exudate including, but not limited to, abrasions, incisions, lacerations, pressure ulcers, infected wounds and draining peristomal wounds can benefit from foam dressings. These products can be used as either primary dressings (making direct contact with the wound) or secondary dressings (used to cover a primary dressing for protective purposes). They’re generally meant for partial- or full-thickness wounds that have moderate or more drainage.

(http://www.advancedtissue.com/guide-foam-dressings/)