Thermal Burns and Severity Assessment

Thermal Burns

• Burns can occur at 111°F (44°C) within 6 hours, and at 140°F (60°C) within 1 second
• The severity of a burn is judged by the depth of the burn and the percentage of body surface area (BSA) involved
• Body surface area (rule of 9's) is calculated as follows:
  • Head and neck: 9%
  • Right arm: 9%
  • Left arm: 9%
  • Right leg: 18%
  • Left leg: 18%
  • Anterior torso: 18%
  • Posterior torso: 18%
  • Perineum: 1%
• For infants up to 1 year old, the skin is still able to retain fluids, so only burns of second degree or worse are used to calculate BSA

Degrees of Burns

• First degree burn (superficial burn)
  • Affects only the epidermis
  • Painful, skin appears red or pink
  • Heals without sequelae as epidermis is regenerated
• Second degree burn (partial thickness burn)
  • Affects epidermis and part of the dermis
  • May be subdivided into:
    • Superficial partial thickness burn: involves epidermis and superficial dermis
    • Deep partial thickness burn: involves epidermis, papillary dermis, and reticular dermis
  • Often see redness and blisters, painful, but may be less painful than expected due to nerve destruction
  • Heals with scarring, often treated with skin grafting to improve outcome
• Third degree burn (full thickness burn)
  • Affects entire thickness of skin, including epidermis, dermis, and variable amount of subcutaneous tissue
  • Leathery white appearance, often insensate (not painful)
  • Generally requires skin grafting
• Fourth degree burn
  • Affects entire thickness of skin, plus underlying muscle or bone
  • Black charred skin

Treatment of Burns

• Maintain adequate oxygenation
• Evaluate airway for evidence of inhalation injury
• Evaluate for carbon monoxide poisoning
• Pain control
• Wound care
• Fluid resuscitation using the Parkland formula
• Goal urine output: 1 ml/kg/hr

Keloid Scars

• Have raised areas and extend beyond the original area of an injury
• May occur after severe burns or ear piercing

Vascular Tumors

• Pyogenic granuloma
  • AKA lobular capillary hemangioma
  • Benign vascular tumor
  • Peak incidence in second and third decades of life
  • Often develops at site of previous injury
  • Display rapid growth
  • Associated with trauma, systemic medications, and pregnancy
• Angiosarcoma
  • Poorly formed vascular spaces lined by endothelial cells with cytologic atypia of nuclei
  • Reddish-brown maculopapular lesion
  • Plaque with crusting on forehead and anterior scalp
  • Poor prognosis: 5 and 10-year survival rates are 34% and 14%, respectively

Nail Changes/Disorders

• Acute paronychia
  • Superficial infection of the proximal and lateral nail folds adjacent to the nail plate
  • Most commonly caused by Staphylococcus aureus or Streptococcus pyogenes
  • Presents with red, swollen, and tender nail folds
  • May develop associated abscess
  • Treatment: topical antibiotics, warm soaks, oral antibiotics, and I&D for abscess
• Onychomycosis
  • Fungal infection of nail due to dermatophyte, yeast, or nondermatophyte mold
  • Most common cause is Trichophyton rubrum
  • Presents with nail discoloration, subungual hyperkeratosis, splitting of nail, onycholysis, and/or nail plate destruction
  • Treatment: oral antifungal therapy, particularly terbinafine
• Subungual hematoma
  • Blood under the nail, usually due to trauma
  • May cause throbbing pain
  • Treatment: drainage/trephination of fresh hematomas, or removal of nail if symptomatic
• Clubbing
  • Thickening of the nail bed's soft tissue, particularly in the proximal end
  • Clinically diagnosed with an exam showing Schamroth sign
  • Associated with altered vasculature, and can be a sign of numerous underlying diseases
• Koilonychia
  • Upward curving of the distal nail plate, resulting in a spoon-shaped nail
  • Associated with iron deficiency anemia, hemochromatosis, trauma, Raynaud disease, and other conditions
• Beau lines
  • Horizontal grooves on the nail plate caused by an interruption of nail bed mitosis
  • Etiologies include severe illness, Reynaud disease, pemphigus, chemotherapy, and others
  • Treatment: no specific treatment other than treating any underlying condition
• Muehrcke lines
  • Transverse, white bands that run parallel to the lunula across the entire width of the nail
  • Etiologies include hypoalbuminemia, nephrotic syndrome, liver disease, and malnutrition
  • Treatment: no specific treatment other than treating any underlying condition
• Terry nails
  • Apparent leukonychia (white discoloration) of all but the most distal 2 mm of the nail bed
  • Etiologies include liver disease, malnutrition, and others