ICD-10 Code L56.0 – Drug phototoxic response (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L56.0 – Drug phototoxic response
What it is
This code identifies a skin reaction caused by a medication that makes the skin unusually sensitive to sunlight. The reaction is phototoxic, meaning it is triggered by light exposure rather than an allergy.
Clinical signs
Typical findings include redness, burning, swelling, and sometimes blistering on sun-exposed skin after taking the drug. Clinical features vary; refer to documentation.
When to use this code
Use L56.0 when the record clearly documents a phototoxic reaction to a medication and links the skin injury to sun exposure. You may also use it when the provider states drug-induced photosensitivity or phototoxic dermatitis. Check documentation if the note does not specify the causal drug or reaction type.
Do not use for
Do not use this code for ordinary sunburn without a medication cause. Do not assign it for allergic drug eruptions or unspecified dermatitis unless the provider documents phototoxicity.
Coding tip
Verify that the medication and the sun-related trigger are documented before assigning L56.0.