ICD-10 Code B85.4 – Mixed pediculosis and phthiriasis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B85.4 – Mixed pediculosis and phthiriasis
What it is
B85.4 identifies an infestation with more than one type of lice, including mixed pediculosis and phthiriasis. Use it when documentation supports both head, body, or pubic lice involvement.
Clinical signs
Typical findings include itching, visible lice or nits, and excoriations from scratching. Clinical features vary; refer to documentation if the note does not clearly identify the lice type or mixed infestation.
When to use this code
Use this code when the provider documents a combined lice infestation rather than a single-site pediculosis. It is appropriate when the record specifically states mixed pediculosis, mixed lice infestation, or pediculosis with phthiriasis. If the note only says “lice,” check documentation before coding.
Do not use for
Do not use B85.4 for a single type of lice infestation, such as head lice alone or pubic lice alone. Do not assign it when documentation is vague or suggests another parasitic skin condition.
Coding tip
Code B85.4 only when the chart clearly supports mixed infestation; otherwise query for the exact lice type.