The harmful substances that cause Ciguatera, Scombroid, and shellfish poisoning are heat stable, so no amount of cooking will protect you from becoming poisoned if you eat fish that is contaminated. Symptoms depend on the specific type of poisoning.
Ciguatera poisoning symptoms can occur anywhere from 2 to 12 hours after eating the fish. They include:
- Abdominal cramps
- Diarrhea (severe and watery)
Shortly after these symptoms develop, you will start to have strange sensations, which may include:
- A feeling that your teeth are loose and about to fall out
- Confusing hot and cold temperatures (for instance, you will feel that an ice cube is burning you, while a match is freezing your skin)
- Headache (probably the most common)
- Low heart rate and low blood pressure (in very severe cases)
- Metallic taste in the mouth
Scombroid poisoning symptoms usually occur immediately after eating the fish. They may include:
- Breathing problems (in severe cases)
- Extremely red skin on face and body
- Hives and itching
There are different types of shellfish poisoning. Below are the most well known types and their symptoms.
Paralytic shellfish poisoning: About 30 minutes after eating contaminated seafood, you may have numbness or tingling in your mouth. This sensation may spread down to your arms and legs. You may become very dizzy, have a headache, and, in some cases, your arms and legs may become temporarily paralyzed. Some people may also have nausea, vomiting, and diarrhea, although these symptoms are much less common.
Neurotoxic shellfish poisoning: The symptoms are very similar to Ciguatera poisoning. After eating contaminated clams or mussels, you will most likely experience nausea, vomiting, and diarrhea. These symptoms will be followed shortly by strange sensations that may include numbness or tingling in your mouth, headache, dizziness, and hot and cold temperature reversal.
Amnestic shellfish poisoning: This is a strange and rare form of poisoning that begins with nausea, vomiting, and diarrhea, which is followed by short-term memory loss, as well as other less frequent neurologic symptoms.