Primary Care Coding Alert

Question: The provider determined an acute rash was an allergic reaction to nickel exposure but mentions nickel as “the irritant” and diagnosed the patient with contact dermatitis. The patient said her skin reacts more dramatically with every exposure. Is this allergic contact dermatitis or irritant contact dermatitis?

Arizona Subscriber

Answer: From the details provided, L23.0 (Allergic contact dermatitis due to metals), which includes allergic contact dermatitis due to nickel, would be the most accurate diagnosis code for this encounter.

The distinction lies in the nature of the rash. “Irritant contact dermatitis is caused by the non-immune-modulated irritation of the skin by a substance, leading to skin changes. Allergic contact dermatitis is a delayed hypersensitivity reaction in which a foreign substance comes into contact with the skin; skin changes occur after reexposure to the substance,” according to the American Academy of Family Physicians (AAFP) (https://www.aafp.org/afp/2010/0801/p249.html).

The provider calls it an allergy, and the patient’s increasingly severe skin reaction exemplifies an immune response and confirms that diagnosis. If the notes hadn’t included that detail, the only choice would have been to query the provider and code accordingly.