Wound dressings

What are wound dressings, and how do they work?

A wound dressing is a material placed over damaged skin. It doesn't heal the wound by itself. Chosen well, it creates a good environment for healing¹.

Dressings that keep a wound moist are now thought to give the best conditions for healing². A little wound fluid (exudate) is a normal part of repair, but too much or too little can slow healing, so the dressing needs to manage it³. Traditional gauze can dry out, disturb the healing wound and damage tissue when it's removed².

A dressing looks after the wound's surroundings, not what caused the wound⁴.

What are wound dressings used for, and how well do they work?

Dressings are used on many kinds of wounds, but no one type has been shown to be best. For chronic wounds (ones that are slow to heal), such as venous leg ulcers, diabetic wounds and pressure ulcers, no single dressing is superior⁵. Foam, alginate and hydrocolloid dressings aren't clearly better than other dressings either⁶.

Some specific results:

• In adults with acute diabetes-related foot ulcers (open sores), silver dressings didn't improve healing at 12 weeks⁷.
• Negative pressure wound therapy (a specialised dressing treatment) may reduce the size of diabetic foot ulcers in adults, but the benefit is uncertain⁸. One trial found it no better than standard moist wound care for closing them⁹.
• For closed surgical wounds in adults, silver and DACC dressings (antimicrobial dressings) probably lower the risk of infection. For other antimicrobial dressings it isn't clear¹⁰.

These results are for particular wounds and for adults, so they may not apply to other wounds or to children.

Is a wound dressing right for me?

Whether a dressing suits you depends on the wound (how wet, dry, deep or infected it is), your circulation and any allergies. A few examples:

• Alginate dressings (very absorbent) suit wounds that weep a fair amount, and aren't suggested for dry wounds⁵. Hydrofiber dressings also shouldn't go on dry wounds⁶.
• Hydrocolloid dressings suit light to moderately weeping wounds, and are recommended for children's wounds because taking them off doesn't cause pain⁵. They aren't suitable for deep wounds, especially infected ones¹¹.
• Dry, dead-looking tissue on the foot or lower leg, and a stable, firmly attached heel scab (eschar), shouldn't be cut away or moistened until a health professional has checked your circulation. The area is kept dry¹.
• Hydrogel, hydrocolloid and silver dressings have been linked with skin allergy¹², and tape is a common cause². Tell whoever dresses your wound about any past reactions. Secondary dressings and tape should be snug, not tight, especially if you have poor circulation in your legs².

What happens when a wound is dressed?

It starts with a look at the wound bed (the wound's surface), how much fluid it makes and any sign of infection. The dressing is then matched to what's found, and complicated combinations are avoided¹.

The dressing is usually sized to reach 2–3 cm beyond the wound edge⁴. Some types, such as alginate, need a second layer over the top¹¹.

There's no set number of changes: it depends on the wound and how much fluid it makes. Needing a change more than three times a day suggests a heavily weeping wound, while 1–2 a day suggests a mild one¹². At each change, look at the skin around the wound for soggy areas. A wound that weeps more when it should be healing needs reassessing¹.

What are the risks and side effects?

Problems with dressings are mostly local, and often come from a poor match between the dressing and the wound². They include:

• skin allergy to the dressing or its tape¹²;
• maceration (soggy, softened skin around the wound), when a dressing absorbs too little for a very weepy wound²;
• pain and tissue damage when a very absorbent dressing is removed from a dry wound²;
• hypergranulation (extra tissue growth) after long use of hydrocolloids on wetter wounds⁶.

No severe side effects were reported with hydrogel dressings in clinical trials¹³. Stop using a dressing or tape that causes a reaction, and ask about a different product².

How do dressings compare with other options?

No single dressing is clearly better than the rest⁵, so the choice rests on the wound's features rather than a product name¹². Moist dressings may speed healing compared with traditional gauze left to dry³. When options are otherwise equal, cost can help decide⁶.

Dressings aren't an either/or choice with treating the cause. Pressure on the area, poor vein circulation, poor nutrition and other health conditions need attention alongside the dressing. If they aren't treated, a wound is unlikely to heal¹.