Diagnosis Coding for Tick Bites

Question:

Why is it so hard to have correct diagnosis coding for tick bites? And, how is it coded?

Answer:

The search function in electronic health records leads clinicians astray. And, diagnosis coding for tick bites  requires two diagnosis codes, because it is an injury. It requires a code from the injury chapter in the first position, that describes the injury and location. And, a code from the external cause chapter that describes how the injury occurred. Does that seem like overkill? Well, it’s ICD-10-CM.

The provider searches for the word “tick” and in many systems, up pops W57.xxxA. Someone helpful has changed the ICD-10 definition to include the word tick, although the ICD-10 definition is “Bitten or stung by nonvenomous insect and other nonvenomous arthropods, initial encounter.” A tick is an arthropod.

But, the problem with that is, W57.xxxA is an external cause code. It may not be submitted in the first position on the claim form, and often it is the only code selected by the provider. The first code should be an S code that describes the location of the bite, such as S70.362A “Insect bite (nonvenomous), left thigh, initial encounter.”

So, it isn’t that it is difficult to code for a tick bite, it’s that there are two steps and the super easy, quick search leads providers to assign the wrong code.

While you’re thinking of diagnosis coding, it’s a good time to review the rules for coding screening labs.

Can you screen for an existing condition? | Diagnosis Coding for Lab Services

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