Burns: Diagnosis

A detailed history will assess the mechanism, duration, and timing of the burn. Physical examination will ascertain burn location and severity, and check for dehydration, disfigurement, and infection. Biopsy is rarely needed to verify infection. Even minor burns can exacerbate such diseases as diabetes, hypertension, and cardiac disease. Fires in enclosed spaces should raise the suspicion for smoke–inhalation injury. Clinicians should also be attentive to injuries that suggest physical abuse.

Burns are classified based on the depth and extent of damage, degree of pain, and swelling.

Partial–Thickness Burns

First–degree burns affect only the epidermis and are characterized by erythema or discoloration, mild swelling, and pain. Sun overexposure is a common cause. Injuries heal in 3 to 6 days.

Second–degree burns affect the epidermis and various portions of the dermis, causing a red or mottled appearance and blisters. Fluid is lost through damaged skin, and the burns are painful and tender since nerve endings are still intact. These burns will blanch with pressure. Injuries heal in 1 to 3 weeks or more. Scarring is uncommon, but there can be long–term skin color changes, although most color changes fade over time.

Full–Thickness Burns

Burns that penetrate beyond the epidermis and dermis are classified as third degree (affecting fat), or fourth degree (affecting muscle, tendon, and bone). Injuries may have a charred appearance and contain white, brown, or black patches. Occasionally they appear red, but will not blanch with pressure. Patients may experience severe pain, but the burns are often not tender, as cutaneous nerve endings have been destroyed. However, partial–thickness burns often surround full–thickness burns and will be painful. Healing occurs only at the wound edges, and scarring is significant, unless skin grafting is done.