MedlinePlus Medical Encyclopedia: Shellfish

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Shellfish

Contents of this page:
Definition Poisonous Ingredient Where Found Symptoms Home Treatment	Before Calling Emergency Poison Control, or a local emergency number What to expect at the emergency room Expectations (prognosis)

Definition

This is poisoning from eating shellfish which have eaten a poisonous dinoflagellate (a single-celled algae found mainly in the ocean).

Poisonous Ingredient

A neurotoxin (affects the nervous system) found in the dinoflagellate.

Where Found

mussels
clams
oysters
scallops

From June through October, shellfish are more likely to eat poisonous dinoflagellate.

Note: This list may not be all inclusive.

Symptoms

body as a whole
- numbness or tingling around the mouth, lips, tongue, and face
- muscle weakness
- paralysis of the legs and/or arms
- lightheadedness
- headache
respiratory
- stop breathing
gastrointestinal
- nausea
- vomiting
- abdominal cramps
- diarrhea

Home Treatment

Shellfish poisoning may be a medical emergency. With sudden or significant symptoms, the person should be taken immediately to an emergency medical facility. You may need to call the local emergency number (such as 911). Otherwise, call Poison Control for appropriate treatment information.

Before Calling Emergency

Determine the following information:

the patient's age, weight, and condition
the name of the product (ingredients and strengths if known)
the time it was swallowed
the amount swallowed

Poison Control, or a local emergency number

If the situation is not clear, they will instruct you if it is necessary to take the patient to the hospital.

Bring the contaminated shellfish with you to the emergency room if so instructed.

What to expect at the emergency room

Some or all of the following procedures may be performed:

Use gastric lavage.
Give a cathartic (a bowel evacuator).
Activated charcoal.
Open and maintain an airway if needed.
Treat the symptoms.

Expectations (prognosis)

Survival past 12 hours usually indicates recovery is likely.
Only a small percentage of people actually die from eating contaminated shellfish.

Update Date: 7/8/2004

Updated by: Cherlin Johnson, M.D., Department of Emergency Medicine, University of Southern California, Los Angeles, CA. Review provided by VeriMed Healthcare Network.

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