T33.011A Superficial frostbite of right ear, initial encounter

ICD-10-CM T33.011A: Superficial frostbite of right ear, initial encounter

ICD-10-CM code T33.011A identifies a diagnosis of superficial frostbite located on the right ear during the initial encounter. Frostbite is tissue damage resulting from cold exposure, with superficial injuries involving the epidermis and potentially the superficial dermis. This specific code captures the right ear laterality and the initial clinical presentation. 2 3

Plain-language overview

Frostbite is a freezing cold injury that causes tissue damage from exposure to temperatures below zero degrees Celsius. Superficial frostbite specifically affects the epidermis and possibly the superficial dermis, representing a largely reversible injury compared to deeper tissue damage. 1 2

What this code represents

Code T33.011A corresponds to the diagnosis of superficial frostbite of the right ear for an initial encounter. The code designation explicitly establishes both the right ear laterality and the initial encounter status for this specific clinical presentation. 3

Documentation considerations

Clinical documentation for frostbite severity relies on the evaluation after rewarming is complete, as many injuries share a similar appearance upon initial presentation. For superficial frostbite, documentation may note clear blister formation and extracellular ice crystals. 2

Superficial frostbite affecting the epidermis and subcutaneous fat will present with pale, white blisters upon rewarming. Because severity cannot be assessed until the rewarming process is complete, documentation of the injury extent depends on post-rewarming clinical evaluation. 1 2

What the sources add

The clinical literature defines the pathology of superficial frostbite as involving clear blisters and extracellular ice crystals, whereas the coding source strictly establishes the anatomical and encounter specificity without detailing the clinical pathology. 2 3

The clinical sources provide detail on the classification of frostbite severity, distinguishing superficial frostbite from frostnip and deep frostbite. The coding source provides the exact diagnostic label mapping to the initial encounter for a right ear presentation. 2 3

Clinical context

Certain pre-existing conditions, including peripheral vascular disease, malnutrition, Raynaud's disease, diabetes mellitus, and tobacco use, may worsen frostbite-related tissue damage. Neuropathy is a long-term sequela that can be associated with both superficial and deep frostbite injuries. 1 2

Coding details

The official display label for T33.011A is superficial frostbite of right ear, initial encounter. The code exists among a distinct group of superficial frostbite codes that specify other right-sided anatomical locations, such as the right arm, right hand, and right foot. 3

Sources

1. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-25.
2. Frostbite: diagnosis, treatment, prognosis, and future directions — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
3. Phecode 1014 · Cancer PRSweb — csg.sph.umich.edu; accessed 2026-07-25.