ICD-10 Code L40.1 – Generalized pustular psoriasis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L40.1 – Generalized pustular psoriasis
What it is
L40.1 identifies generalized pustular psoriasis, a severe psoriasis variant marked by widespread sterile pustules on inflamed skin. Use it when the record specifically documents this generalized form.
Clinical signs
Typical findings include diffuse erythema with numerous small pustules, often recurring in flares. Clinical features vary; refer to documentation for extent, distribution, and whether the presentation is generalized.
When to use this code
Use L40.1 when the provider diagnoses generalized pustular psoriasis or documents a flare of this specific subtype. It fits outpatient, inpatient, and emergency records when the condition is clearly named. If the note only says “psoriasis” or “pustular rash,” check documentation before assigning this code.
Do not use for
Do not use this code for plaque psoriasis, palmoplantar pustulosis, or localized pustular eruptions unless generalized pustular psoriasis is documented. Check documentation if the diagnosis is uncertain.
Coding tip
Code the condition only when the clinician explicitly states “generalized pustular psoriasis”; otherwise, query for clarification.