Thermal burns and scalds

It is customary for all major burns to be managed by general or plastic surgeons in regional burn units with access to intensive care facilities. A scald is a burn caused by moist heat. First-degree burns involve only the epidermis and papillary dermal blood vessels and produce pain, redness and swelling. In second-degree or partial skin thickness burns, the epidermis blisters and becomes necrotic. In third-degree or full thickness burns, the necrosis is deeper and pain may be absent if nerve endings are destroyed. If the wound is anaesthetic, it is likely that the skin appendages will also have been destroyed and this has important implications for healing.


Patients with extensive (greater than 9% of body surface area) and deep burns are prone to hypovolaemia and shock. The management of these conditions is beyond the scope of this text.

In first-degree burns, acantholysis occurs and healing proceeds quickly from the underlying intact epidermis. Re-epithelialisation of partial thickness burns occurs both from the epidermal appendages (hair follicles and sweat glands) and the wound edge. Full thickness burns can only heal from the wound edge and do so slowly, often with disfiguring wound contraction and associated joint contractures. Large full thickness burn wounds are best treated by skin grafting, either after the slough has separated or by excision and grafting 4 to 6 days after the burn.

First aid


Immediate treatment of burns consists of immersion in cold running water for a minimum of 10 to 15 minutes.


Charred clothing that is adherent to the burn wound should not be disturbed. It is likely to have been sterilised by the heat.

The area should then be covered by any available clean material, such as polythene film or aluminium foil, pending transfer.

Pain may be severe and pain relief may require morphine. Patients should be assessed for shock and treated accordingly.

Local treatment

The aim of local treatment is to achieve skin cover as soon as possible, to prevent infection, and to minimise scarring, deformity and loss of function.

In minor burns the treatment is commenced immediately. The burn is cleaned, loose skin is removed, tense blisters are pricked and the blister roof is allowed to collapse down onto the wound.

A broad-spectrum antiseptic cream active against pseudomonas may then be applied to the wound to prevent infection. Use

silver sulfadiazine (SSD) 1% cream.


This is not required for very superficial burns, and may even delay re-epithelialisation. It is only re-applied at dressing changes.

If the burn is superficial and there is minimal ooze, a dressing to promote re-epithelialisation (hydrocolloid sheets, hydrogel sheets, transparent films, foam sheets can be placed over the burn. Alternatively, a nonwoven retention adhesive material, eg Fixomull or Hypafix, can be placed over the epithelialising burn in place of a dressing. The frequency of dressing changes is dictated by the amount of ooze and the desire to monitor the wound for infection. Some wounds will require second daily dressings initially, while others can have the dressing left in place for up to a fortnight. In general, the fewer dressing changes the better.

If the burn is deep, there is likely to be considerable exudate for a week or more. A broad-spectrum antiseptic cream, such as SSD 1%, should be applied directly to the burn. A nonadherent neutral dressing, should be placed over the cream and then a layer of absorbent gauze placed over the dressing. For large burns, another layer of absorbent cotton wool can be placed over the gauze and held in place with a crepe bandage. Should the wool become saturated, a further layer can be placed over the top without removing the original dressing. This dressing should be changed every 2 to 4 days. Analgesic cover may be required for the dressing changes.

If a full thickness burn is present, the area of dead skin will turn black rapidly. Treatment is then aimed at removing the slough. Surgical debridement is the most effective method but debriding agents or autolytic debridement aided by the use of amorphous hydrogels may be tried.

Many aspects of burn management are complex and doctors should have a low threshold for seeking advice from specialist burn units.

Chemical burns

The principles of management of chemical burns are the same as for thermal burns, except for the first aid. Chemical burns require thorough irrigation with water to remove any residual chemical. Acetic acid 3 to 5% (1 in 10 dilution of vinegar) may be applied to alkali burns, while a solution of several tablespoons of sodium bicarbonate in a litre of water may be applied to acid burns. Phosphorus burns may be treated with copper sulfate 2% solution, followed by sodium bicarbonate solution. Caustic burns, eg with phenol, should be neutralised with glycerol before being washed with water.

Radiation burns

These are generally seen in patients receiving therapeutic radiotherapy and are usually managed by the radiotherapist. Healing by secondary intention may take a number of weeks, and dressings such as amorphous or sheet hydrogels, may be required.

Cold injury

A burn is a wound in which there is coagulative necrosis of the tissues. As cold injuries such as frostbite also cause coagulative necrosis, it is appropriate to consider cold injury here. The most common cold injury seen in Australia is iatrogenic, following liquid nitrogen cryosurgery.

The special characteristics of the cold injury following cryosurgery impact on the wound care. The injury preferentially affects the epidermis, while the collagen and elastin of the dermis are relatively resistant. Therefore the wounds do not heal with contraction. Textural alteration of the skin is also rare, but permanent hypopigmentation is common due to the relative hypersensitivity of melanocytes to cold injury. Infection is also rare, for reasons that are not clearly understood.

These wounds are best left open to the air. A dusting powder may be used to dry up exudate or a nonadherent neutral dressing may be placed over the wound to absorb the exudate, which lasts about 2 days. These wounds almost invariably heal, despite their somewhat alarming initial appearance, and minimal intervention is appropriate.


In abrasions, only part of the epidermis has been removed and in general these wounds heal without scarring. Any foreign material should be meticulously debrided and a broad-spectrum topical antiseptic applied, eg povidone iodine. If the wound is dry, a dressing to promote re-epithelialisation should be applied and changed as infrequently as possible. If oozing, a neutral nonadherent dressing should be applied and changed every 2 to 4 days.


Traumatic wounds


Cleaning and debridement of wounds is important in preventing infection. A topical antiseptic, eg povidone-iodine, may be used at the first dressing only, to reduce the risk of infection. Elevation and immobilisation may be helpful.

Antibiotic therapy may be necessary, depending on the severity, the site of injury and the likelihood of infection occurring. If obviously infected, a wound swab should be taken. Delaying primary wound closure may have to be considered if infection is evident or suspected.


Surgical wounds


Surgical wounds may heal either by primary or secondary intention. Sutures, staples or steri-strips are used to encourage primary healing. Sutures should be left in place long enough for the epidermis on the opposing edges of the wound to join, but not too long, as they may become a focus for wound infection or cause dots at the side of the scar, marking their exit points from the skin. In general, sutures should be removed at the following times:

           on the face after 5 to 7 days

           on the arms and trunk after 7 to 10 days

           on the legs after 14 days.

At the time of suture removal, the dermis of the opposing edges of the wound is unlikely to have fused, and the wound will only have about 20% of its final strength. Eighty per cent of the final strength is usually achieved at 6 weeks, and full strength may take 6 to 9 months. Thus, the period following suture removal is vulnerable for wound dehiscence if deep sutures have not been used. This should be anticipated and patients warned to not place undue tension on the wound for 6 weeks and to curtail physical activities appropriately. Taping the wound at the time of suture removal is also a wise precaution.

Complications of surgical wounds include wound infection (see Postoperative wound infections) wound dehiscence, flap or graft failure, hypertrophic scarring, and bleeding. The management of these is discussed in Table . Bleeding that is difficult to control often occurs in the context of anticoagulant therapy, uraemia, hypertension and occult bleeding diatheses such as Von Willebrand’s disease.


Complications of surgical wounds (Table )



- early

·            apply pressure

·            insert drain tubes

·            explore the wound, remove any haematoma and subsequent intraoperative haemostasis.

·            haemostatic alginate dressing

- late

·            as above, but awareness of the possibility of occult wound infection is important.



·            debride dead tissue and remove haematoma

·            systemic antibiotic therapy


- early

·            resuture

·            maintain a moist environment with appropriate dressings

- late

·            leave wound to heal by secondary intention

·            resuture following debridement of the wound

·            maintain a moist environment with appropriate dressings

Flap or graft failure


·            leave wound to heal by secondary intention

·            resuture following debridement of the wound

Hypertrophic scarring


·            intralesional corticosteroid injection with triamcinolone 10mg/mL, repeated at monthly intervals

·            pressure on the scar – polyurethane foam dressing with compression

·            cryosurgery (needs to be repeated at monthly intervals)

·            immobilise the wound with surgical tape or silicon sheeting (in general, re-excision is not advocated due to the risk of recurrence in the new scar)



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