ICD 10 Coding Alert

Corrosion or burn? Here’s why it matters.

Patients who report to the ED with burns have always presented a coding challenge. Reporting burn codes is involved, and you’ll have to extend diagnoses to the 7th character in most cases.

You’ll also have to distinguish between a corrosion and a burn, for coding purposes. This all adds up to a tall order, if you don’t know what you’re looking for.

Check out this primer on coding for burns of all kinds.

Know if Injury Is Corrosion or Burn

As ICD-10 now includes separate codes for each, you’ll need to note which type of injury the patient suffered before choosing a diagnosis code: a corrosion or thermal burn. “Corrosions are burns that result from chemicals; whereas thermal burns are those that result from direct heat being applied to the skin, which excludes sunburn,” explains Carol Pohlig, BSN, RN, CPC, manager of coding and education in the department of medicine at the Hospital of the University of Pennsylvania in Philadelphia.

The rules for coding corrosions and burns are the same, but the codes you will use aren’t. Corrosion codes are listed after burn codes in each anatomical ICD-10 listing. For example, in the T20.- (Burn and corrosion of head, face, and neck) code family, ICD-10 lists burn codes T20.0- (Burn of unspecified degree of head, face, and neck) through T20.3- (Burn of third degree of head, face, and neck). Then, ICD-10 lists corrosion codes T20.4- (Corrosion of unspecified degree of head, face, and neck) through T20.7- (Corrosion of third degree of head, face, and neck) for the same anatomical area.

Note Burn Severity

Your hunt for the most accurate burn diagnosis code will begin with the first three characters, which will identify the severity of the burn and the general anatomical location. For example, T20.2- (Burn of second degree of head, face, and neck).

You’ll need to know the difference between first-, second-, and third-degree burns, for coding purposes.

According to Pohlig: “First-degree typically results in redness to the area and involves only the outer layer of skin, or epidermis. The area can be dry and painful.

“Second-degree typically results in blistering of the skin and extends to parts of the middle layer of skin, or dermis. Third-degree involves multiple layers of the skin and can extend beyond the dermis to the subcutaneous tissue, typically referred to as full thickness.”

Find and Mark Burn Location

Once you’ve decided whether you’re coding a corrosion or burn and gotten the general anatomical location, you’ll start to get more detailed, drilling down to the 5th character to identify the burn site more specifically. This narrows the anatomical location and puts a finer point on just where the patient is suffering burns.

Example: A patient suffers a first-degree burn to the chest wall. You’d start at T21.1- (Burn of first degree of trunk) and then get more specific with T21.11- (Burn of first degree of chest wall).

Report 6^th Character, if Applicable

For burn diagnosis codes that indicate laterality, you will use the 6th character to mark that feature. For example, T22.121- (Burn of first degree of right elbow). If the ICD-10 code doesn’t account for laterality, you’d use the placeholder “X” for the 6th character.

Remember: If there is no 6th character for your burn ICD-10 code, the placeholder is necessary because all burn diagnosis codes require a 7th character, which will almost always be “A = initial encounter.”

Use T30-T32 Codes Properly

To report burns that have no detail in the documentation, you’ll need a code from the “Burns and corrosions of multiple and unspecified body regions (T30-T32)” set.

“T30.- [Burn and corrosion, body region unspecified] codes would only be used when no detail is present in the documentation as this code family refers to burns and corrosions where neither the body region or degree are specified,” explains Pohlig.

Ideally, you would use the T31.- (Burns classified according to extent of body surface involved) and T32.- (Corrosions classified according to extent of body surface involved) codes “as an adjunct to anatomically defined burn codes T20-T25,” explains Pohlig. This will provide more information on the patient’s burns: specifically, the total body surface area (TBSA) of the burns and the amount of those burns that are third-degree.

As a last resort, you could also use T31 and T32 codes as the primary diagnosis if the anatomical area has not been documented, but the TBSA and percentage of third-degree burns are listed. This is not best practice, but ICD-10 recommends it when the documentation is lacking. “This category is to be used as the primary code only when the site of the burn is unspecified,” according to the Notes section beneath T30-T32.

Chris Boucher, MS, CPC, Senior Development Editor, AAPC