First, histamine poisoning, dead crabs will produce a lot of histamine, and people will have histamine poisoning when eating dead crabs, because histamine is an allergic poison, which can also be said to be allergic food poisoning. Don't think that just eating a little dead crab meat doesn't matter. People who are allergic to histamine can cause a reaction even after taking a bite. For example, some people will have symptoms after eating dead crab 10 minutes to 3 hours, such as red cheeks.

Secondly, bacterial infection is also one of the important causes of poisoning. Generally speaking, the living environment of wild river crabs is not as good as artificial and sea crabs. Once they die, bacteria in and out of the body will multiply, decompose crab meat and produce toxins. At this time, once people eat dead crabs, the risk of bacterial infection is higher and bacterial infection is more likely to occur.

Extended data

The Dietary Guide for China Residents suggests that everyone should eat 40 to 75 grams of aquatic products every day, so don't eat more than one crab every day. People with allergies, hyperuricemia or gout, pregnant women, the elderly, children and the infirm, it is best to eat less or not to eat crabs. If caught by a crab, wash the wound with water immediately and disinfect it with iodophor. If it is swelling and bleeding, go to the hospital quickly.

References:

People's Network-Why do you have to eat live crabs when eating crabs? Eating dead crabs is really harmful.