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.
Specialty: Toxicology, Emergency Medicine, Critical Care