ICD-10 Code H10.21 – Acute toxic conjunctivitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H10.21 – Acute toxic conjunctivitis
What it is
H10.21 identifies acute toxic conjunctivitis, an acute inflammation of the conjunctiva caused by exposure to an irritating or toxic substance. Use it when the documentation clearly links the eye irritation to a chemical or other toxic exposure.
Clinical signs
Typical findings include red, irritated eyes with tearing, burning, and conjunctival swelling after exposure. Clinical features vary; refer to documentation for the specific irritant and whether one or both eyes are involved.
When to use this code
Use this code when the provider documents acute conjunctivitis due to a toxic or irritant exposure, such as a chemical splash or contact with a harmful substance. It also fits cases described as toxic, irritant, or chemical conjunctivitis when the diagnosis is acute. If the record does not clearly identify the cause, check documentation before assigning this code.
Do not use for
Do not use H10.21 for allergic, infectious, or chronic conjunctivitis, or for nonspecific eye redness without a documented toxic cause. Check documentation if the condition is described only as conjunctival irritation.
Coding tip
Link the diagnosis to the documented exposure, because the toxic cause is what supports this code.