ICD 10 Coding Alert

Question: I just started at an allergist’s office and sometimes we see patients who come in for testing, but do not test positive for anything. For example, I just read a chart where a child came in for an initial appointment while experiencing chronic diarrhea and their parent wanted to make sure they weren’t allergic to any of the foods they commonly eat. This child did not react to any of the foods tested in a skin prick test. If the child doesn’t react to anything, would I still use a diagnosis code if there aren’t any confirmed allergies?

Maryland Subscriber

Answer: In this situation, you’d code the encounter with the appropriate evaluation and management (E/M) code and CPT^® code to capture the skin prick test(s).

Regarding ICD-10-CM coding: The scenario you describe involves no reactions, but you’ll still want to describe, with codes, the reason the allergist performed the testing. So, look to signs and symptoms that are documented, the reason for the visit, and ways that the testing supports medical necessity. In this case, the patient came in complaining of chronic diarrhea, which you can report with R19.7 (Diarrhea, unspecified).

If the provider clearly documents concern about a food reaction with phrases like “concern for possible food allergy” or “suspected adverse food reaction,” you can report T78.19XA (Other adverse food reactions, not elsewhere classified, initial encounter). However, you should only report this code when the provider documents a suspected or clinically assessed food reaction, not just parental concern.

If the provider documents that the patient exhibits no symptoms, and the parent is just interested in knowing the child’s allergy status via a screening, you could report Z13.89 (Encounter for screening for other disorder).

Finally, do not code a food allergy or related condition if the provider documents that allergy has been ruled out.

Rachel Dorrell, MA, MS, CPC-A, CPPM, Production Editor, AAPC