Toxic effect of harmful algae and algae toxins, acc, subs

This code signifies a patient presenting for follow-up care or treatment of an adverse health event caused by accidental exposure to harmful algae or their toxins. The initial exposure and acute symptoms have already been addressed, and the patient is now receiving ongoing management for residual effects or complications.

Apply this code when documenting subsequent encounters for conditions such as persistent neurological symptoms, dermatological issues, or gastrointestinal disturbances that arose from unintentional contact with harmful algal blooms (e.g., red tide) or contaminated seafood. This includes follow-up visits for monitoring recovery, managing chronic symptoms, or addressing delayed complications.

• Ensure the encounter is for follow-up care, not the initial acute presentation.
• Verify documentation explicitly states the exposure was accidental and due to algae/algae toxins.
• Always code the specific manifestation of the toxic effect (e.g., gastroenteritis, dermatitis) as a primary diagnosis, with this code as a secondary diagnosis.