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Symptoms and Signs of Shellfish Poisoning

Doctor's Notes on Shellfish Poisoning

Shellfish poisoning is toxic poisoning that occurs when shellfish (mainly oysters, clams, scallops or mussels) are eaten by humans. Most shellfish come from saltwater habitats, but some species inhabit freshwater, and both can cause shellfish poisoning. Shellfish poisonings are categorized into four groups based on the specific toxins or chemicals that poison humans: amnesic shellfish poisoning (ASP), diarrheal shellfish poisoning (DSP), neurotoxic shellfish poisoning (NSP), and paralytic shellfish poisoning (PSP).

Symptoms of amnesic shellfish poisoning include permanent short-term memory loss, brain damage, and death. Symptoms of diarrheal shellfish poisoning include diarrhea, nausea, and vomiting. Symptoms of neurotoxic shellfish poisoning include slurred speech, nausea, and vomiting. Symptoms of paralytic shellfish poisoning include numbness and tingling sensations, coordination loss, speech defects, nausea, vomiting, and death.

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 3/11/2019


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.