Other shellfish poisoning, undetermined, initial encounter

This code signifies an adverse health event resulting from the consumption of shellfish, where the specific type of shellfish or toxin is not definitively identified. The patient is presenting for initial treatment of the poisoning symptoms.

Apply this code when a patient presents with symptoms consistent with shellfish poisoning (e.g., nausea, vomiting, diarrhea, neurological symptoms) after consuming shellfish, but the medical record does not specify the exact type of shellfish (e.g., oysters, clams, mussels) or the causative toxin. This is for the initial visit for this particular poisoning episode.

• Ensure documentation clearly indicates "undetermined" or unspecified shellfish/toxin.
• Do not use if a specific type of shellfish poisoning (e.g., paralytic, neurotoxic) is documented.
• The "A" indicates an initial encounter; select subsequent or sequela codes for follow-up care.