Neurotoxic Shellfish Poisoning (NSP) may occur following ingestion of shellfish that have fed on dinoflagellates producing neurotoxins. It is uncommon and rarely lethal.
Toxins: brevetoxins, which are heat stable, lipid soluble, acid stable, base labile.
Timing:
(1) onset is from minutes after ingestion up to 3 hours
(2) duration 2 to 3 days
Presenting symptoms (may be missed if the patient is sleeping at the time of onset):
(1) nausea
(2) abdominal pain
(3) diarrhea
Severity of Syndrome
Symptoms
mild to moderate
circumoral paresthesias
trunk paresthesias
limb paresthesias
ataxia or incoordination
vertigo
headache
bronchospasm (if inhaled as an aerosol)
severe
bradycardia
convulsions
dilated pupils
Paralysis does not occur.
Mortality rate: none reported
If more than one person was exposed, the spectrum of findings amongst all of the persons may help reach a final diagnosis.
Management:
(1) Supportive care is usually adequate.
(2) Anticonvulsants may be needed if seizures occur.
(3) Respiratory support may be needed in a few patients with seizures.
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