Toxic effect of venom of hornets, undetermined, init encntr

This code signifies a patient presenting with an adverse systemic reaction to hornet venom, where the intent (e.g., accidental, assault) of the exposure is not documented or cannot be determined. It indicates the initial phase of treatment for such a toxic effect, which may range from localized swelling to anaphylaxis.

Apply this code when a patient seeks medical attention for symptoms following a hornet sting, and the provider's documentation does not specify whether the sting was accidental, intentional self-harm, or an assault. This is appropriate for the first encounter for this specific injury.

• Always assign an external cause code (e.g., W57.XXXA) in conjunction with this code to fully describe the circumstances of the sting.
• Ensure the "A" for initial encounter is appropriate; subsequent care for the same sting would use "D" or "S."
• Verify documentation explicitly states "hornet" venom; other insect venoms have different codes.