Angioneurotic edema, initial encounter

This code signifies the initial presentation of angioedema, a condition characterized by sudden, localized swelling of the deeper layers of the skin and mucous membranes. Unlike urticaria (hives), angioedema typically involves deeper tissue and is not usually itchy, though it can be painful or cause a burning sensation. It often affects the face, lips, tongue, larynx, extremities, and gastrointestinal tract.

Use this code when documenting the first time a patient presents with angioedema, regardless of the underlying cause (e.g., allergic, hereditary, acquired, drug-induced, or idiopathic). This code is appropriate for the initial diagnostic workup and management of an acute angioedema episode. Subsequent encounters for the same episode or for follow-up care would utilize a different seventh character.

• Always assign an additional code to identify the specific type or cause of angioedema, if known (e.g., drug-induced, allergic reaction).
• Ensure the seventh character "A" (initial encounter) is used only for the first time the patient is seen for this condition.
• Distinguish angioedema from urticaria; while they can co-occur, angioedema involves deeper tissue swelling.