Idiopathic urticaria

This code represents a skin condition characterized by the sudden appearance of itchy, raised welts (hives) or wheals, where the underlying cause cannot be identified. It is a diagnosis of exclusion, meaning other potential causes of urticaria have been ruled out.

Use this code when the patient presents with recurrent episodes of urticaria for which no specific allergen, physical trigger, or systemic disease can be identified after appropriate diagnostic workup. Documentation should clearly state "idiopathic urticaria" or "chronic urticaria of unknown etiology."

• Ensure documentation explicitly states "idiopathic" or "of unknown cause" to support this specific code.
• Do not use this code if a specific cause (e.g., allergic reaction, physical urticaria) is identified; instead, code the specific type of urticaria.
• Consider sequencing this code as the primary diagnosis when it is the reason for the encounter and no other underlying condition is being treated.