Nail disorders in diseases classified elsewhere

This code represents nail abnormalities that arise as a manifestation or complication of an underlying systemic disease or condition. It encompasses various changes in nail appearance, texture, or growth directly attributable to a primary illness classified elsewhere in ICD-10-CM. These nail disorders are not primary nail diseases but secondary effects of another medical condition.

Use this code when documentation clearly links a nail disorder (e.g., clubbing, pitting, discoloration, onycholysis) to an underlying systemic disease such as psoriasis, thyroid disease, inflammatory bowel disease, or certain infections. The medical record must explicitly state the causal relationship between the systemic condition and the nail manifestation.

• Always sequence the underlying systemic disease first, followed by this code to indicate the manifestation.
• Do not use this code for primary nail disorders (e.g., onychomycosis, ingrown nail) that are not secondary to another condition.
• Ensure documentation specifies the type of nail disorder and its direct association with the primary diagnosis.