All About Fish, Shellfish Allergies
It’s an experience that has puzzled thousands of seafood lovers across Canada and around the world: You’ve eaten fish and shellfish all of your life with no ill effects, and then one day, you’re eating some tasty tidbit from the sea – maybe some jumbo shrimp, some butter-drenched lobster, or some fresh-caught salmon – and suddenly, you don’t feel so good.
Maybe you feel like you’re going to be sick to your stomach, or feel your throat tightening and your lungs beginning to wheeze. You may feel flushed and hot as your face turns beet red. Maybe you break into hives from head to toe, or feel like you’re going to pass out as your heart takes off like a bullet train.
Chances are that you are having an allergic reaction to seafood – the most common culprits in the allergy world.
What’s The Problem?
Seafood can be divided into two groups: shellfish and fish. Shrimp is behind most of the reactions, and shellfish as a group – which can include oysters, mussels, scallops, squid, crab, snails and many more – tends to be more problematic than finned fish. (In one survey by FAAN and Mount Sinai researchers, two per cent of respondents reported a shellfish allergy, whereas just 0.4 per cent reported an allergy to fish.)
Symptoms of a reaction to seafood can include flushing and swelling in the face, mouth and throat; digestive tract symptoms such as nausea and diarrhea; itching and hives; difficulty breathing; lightheadedness or faintness; a sudden drop in blood pressure and a rapid heartbeat.
In severe cases, a person may experience anaphylactic shock, a reaction that includes one or more of the body’s systems and can result in cardiac arrest and death.
A whopping 2.3 per cent of Americans are allergic to some form of seafood, whether it’s fish, crustaceans or mollusks. In Canada, 1.69 per cent of people are allergic to shellfish and 0.48 per cent are allergic to fish. What’s more, a 15-nation study showed the incidence is similarly high right around the world.
See: Seafood Allergy Statistics
Because of its high incidence, Health Canada has named both shellfish and fish “priority food allergens”, which means tougher labeling rules for Canadian manufacturers. Other regions, including the United States and Europe, have also included seafood on their lists of top allergens.
See: Label Aware
It’s a Grown-Up Thing
What’s different about seafood allergies is that they are largely an adult phenomenon. In Canada, 1.69 per cent of adults have shellfish allergy, compared to just 0.5 per cent of children. According to the FAAN-Mount Sinai survey, 2.8 per cent of adults in the United States reported a seafood allergy, as compared with just 0.6 percent of children.
This can be especially problematic, since most adults are accustomed to eating seafood, so when they react, it doesn’t seem to make sense to them. Often they dismiss earlier, less severe reactions as food poisoning or simply “something they ate”; but then they get a tough lesson in science as the allergy grows more severe and the reactions more extreme.
Unfortunately, once an adult develops a shellfish allergy, he or she likely has that allergy for life.
Next page: Seafood Allergy Myths