Q&A: Navigating clinical uncertainty, coding for acute skin failure, pressure injuries

Q: What clinical factors distinguish acute skin failure from a pressure injury, and how should the two conditions be approached from an ICD-10-CM coding perspective?

A: This can be a difficult question to answer because there is no universally accepted or validated clinical definition or diagnostic checklist for acute skin failure. Although experts generally agree that acute skin failure and pressure injuries are distinct clinical entities, there are currently no nationally standardized diagnostic criteria that allow a coder to definitively distinguish the two based on a specific set of clinical indicators.

In general, acute skin failure is described as a manifestation of systemic physiologic dysfunction in which the skin and underlying tissues are unable to maintain normal function, potentially resulting in tissue injury or necrosis. It is often associated with critically ill or dying patients and may occur in association with severe hypoperfusion. However, hypoperfusion or an ICU admission should not, by themselves, be considered diagnostic criteria for skin failure.

Other clinical circumstances discussed in association with skin failure include the use of vasopressors, immunosuppressive medications, and chemotherapeutic agents, as well as severe systemic illness and other conditions that impair tissue perfusion or the body's ability to maintain skin integrity. These factors should be viewed as clinical context rather than definitive diagnostic criteria.

This is an area where coders should be cautious. There is no dedicated ICD-10-CM code titled "acute skin failure." When the provider documents skin failure as a manifestation of an underlying disease or condition, the applicable ICD-10-CM code should be assigned from the Alphabetic Index and Tabular List, applying any instructions to code first or code also other conditions. Coding Clinic guidance has addressed the use of code L99 (other disorders of skin and subcutaneous tissue in diseases classified elsewhere) when the documentation supports the relationship between skin failure and underlying disease or condition. Code L98.9 (disorder of the skin and subcutaneous tissue, unspecified) may be an option when a more specific code is not supported, but querying the provider is preferable to obtain detailed clarification.

The distinction between skin failure and pressure injuries is important. A pressure injury or ulcer has an identifiable external mechanism involving pressure that can be used as a diagnostic criterion, and ICD-10-CM provides specific codes in category L89.- (pressure ulcer) based on the anatomic site, laterality, and stage. For example, a documented stage 3 pressure ulcer of the sacral region would be reported with code L89.153, while a stage 4 pressure ulcer of the right heel would be reported with code L89.614. The specific code must be selected based on the provider's documentation and the ICD-10-CM Tabular List.

By contrast, acute skin failure is generally described as a consequence of an underlying systemic physiologic dysfunction rather than an injury attributable to pressure. There can be considerable clinical overlap, particularly with wounds sometimes described as Kennedy terminal ulcers, which may develop rapidly in patients who are approaching the end of life. The presence of a rapidly developing wound, however, does not automatically establish skin failure either. The provider must determine and document the diagnosis based on the patient’s overall clinical circumstances.

Ultimately, the presence of systemic illness, hypoperfusion, vasopressor use, rapid wound development, or an end-of-life clinical picture should not be used in isolation to assign a diagnosis of acute skin failure. The provider’s documented clinical diagnosis, supported by the patient’s circumstances, remains essential to appropriate coding practices.

Editor’s note: This question and answer were originally published in JustCoding, which adapted them from a discussion with Lynette Byerly, BSN, RN, CCDS, CCS, CDI education specialist at ACDIS/HCPro, on The ACDIS Podcast.