T24.20XA

Burn of second degree of thigh and leg, unspecified site, initial encounter

T24.20XA is a specific ICD-10-CM code used for the initial encounter of a patient presenting with a second-degree burn of the thigh and leg at an unspecified site. A second-degree burn, also known as a partial-thickness burn, involves the destruction of the epidermis and extends into the underlying dermis. These burns are characterized by significant pain and the formation of blisters. The 'unspecified site' designation indicates that while the injury is located on the thigh or leg, the precise anatomical sub-location (such as anterior thigh, posterior leg, or specific aspect of the limb) has not been detailed in the medical record. The 7th character 'A' signifies the initial encounter, which is used while the patient is receiving active treatment for the burn, including emergency department care, surgical evaluation, or initial dressing changes.

Clinical Symptoms

  • Intense localized pain
  • Formation of blisters (bullae)
  • Skin that appears moist or weeping
  • Deep redness or mottled appearance of the skin
  • Localized edema (swelling)
  • Blanching upon pressure with slow capillary refill
  • Sensitivity to air currents and light touch
  • Possible peeling of the epidermal layer

Common Causes

  • Scalding from hot liquids (water, oil, grease)
  • Direct contact with hot objects (stoves, irons, exhausts)
  • Exposure to open flames or flash fires
  • Chemical burns from acidic or alkaline substances
  • Excessive exposure to ultraviolet radiation (severe sunburn)
  • Friction burns (e.g., road rash)
  • Electrical accidents causing thermal injury

Documentation & Coding Tips

Specify the exact Total Body Surface Area (TBSA) using the Rule of Nines or Lund-Browder Chart.

Example: Patient evaluated for a second-degree burn of the right lower limb after contact with boiling water. Physical exam shows partial thickness injury to the posterior thigh and calf, encompassing approximately 9 percent TBSA. Associated morbidity: Chronic obstructive pulmonary disease (COPD), which is currently stable but requires monitoring for respiratory complications during recovery. ICD-10 Coding: T24.20XA, T31.0, J44.9.

Billing Focus: Requires an additional code from category T31 to identify the total body surface area involved, even if the burn is less than 10 percent.

Document the precise anatomical location and laterality to move beyond unspecified site codes.

Example: Initial encounter for a second-degree burn of the left lateral thigh, approximately 4 percent TBSA. The wound exhibits blistering and significant pain. Patient is a non-smoker with no relevant comorbidities. We will initiate local wound care and topical silver sulfadiazine. Billing Focus: Identification of left laterality. Coding: T24.212A, T31.0.

Billing Focus: Laterality (left vs right) and specific site (thigh vs lower leg) must be documented to avoid the unspecified T24.20XA code when possible.

Include the external cause of the burn to support medical necessity and insurance liability determination.

Example: A 45-year-old female presents with second-degree burns of the unspecified site of the right leg (T24.20XA) sustained while cooking in her home kitchen when a pan of oil caught fire. Area involves 5 percent TBSA. No secondary infection. Associated history: Obesity with BMI of 32. External Cause: X10.2XXA. TBSA: T31.0.

Billing Focus: External cause codes (V-Y codes) are required by many payers to identify liability and are essential for a complete clinical picture.

Clearly distinguish between partial thickness (second-degree) and full thickness (third-degree) involvement.

Example: The patient has a 2nd degree burn of the thigh and leg involving 12 percent TBSA. There are no areas of 3rd degree burn. Wounds are blanchable and hypersensitive to touch. Patient has underlying Type 2 Diabetes Mellitus with peripheral neuropathy, which may impair perception of further injury. Coding: T24.20XA, T31.10, E11.40.

Billing Focus: The depth of the burn (degree) determines the code category; 2nd degree (T24.2) vs 3rd degree (T24.3).

Document the encounter status accurately as initial, subsequent, or sequela.

Example: Initial encounter for a partial thickness thermal burn of the lower limb. Patient accidentally spilled hot coffee while sitting. 2 percent TBSA involved. Wound debrided. Patient also treated for essential hypertension. Coding: T24.20XA, T31.0, I10, X10.0XXA.

Billing Focus: The 7th character A (initial) is used as long as the patient is receiving active treatment for the burn.

Relevant CPT Codes