Toxic effect of venom of brown recluse spider, undet, init

This code signifies a patient presenting with symptoms resulting from exposure to brown recluse spider venom, where it is not specified if the exposure was accidental or intentional. The "initial encounter" designation indicates that this is the first time the patient is receiving active treatment for this specific toxic effect.

Apply this code when documentation confirms a brown recluse spider bite and subsequent toxic effects, but the medical record does not clarify the intent (e.g., accidental bite vs. self-harm). This is appropriate for the initial visit where diagnostic workup and treatment for the envenomation are being provided.

• Ensure the documentation explicitly mentions a brown recluse spider.
• Only use the "undetermined" character when intent is truly unspecifed in the medical record.
• Pair with external cause codes (e.g., W57.XXXA for bite or sting by nonvenomous arthropod) to provide further detail about the incident.