Paralytic Shellfish Poisoning
Ingestion of toxic shellfishes and other aquatic animals could result in a characteristic syndrome more commonly called as “red tide”.
Saxitoxin is the toxin causing the symptoms that come from a dinoflagellate (algae) ingested by the shellfishes and other sea fishes during filter-feeding.
This Saxitoxin is a derivative of tetrahydropurine and one of the most lethal poisons known.
It is estimated that 0.1 mg is lethal to man. It produces its toxicity by binding to the sodium channel receptors to block sodium movement.
So what do we see in patients with paralytic shellfish poisoning?
In 15 minutes to 12 hours post-ingestion of contaminated sea products with an average of 3 hours, symptoms occur and the following may be seen:
– tingling sensation or numbness around the lips
– the sensation or numbness gradually spreads to the face, neck, upper and lower extremities
– there is generalized body weakness manifested in children like inability in getting up
– floating sensation
– ataxia
– dizziness
– dyspnea
There is no known specific antidote to this kind of poisoning; treatment is purely supportive.
Usually patients who do not develop severe symptoms within 24 hours post – ingestion recover spontaneously.
However, some may have weakness that can persist up to several weeks after the illness.