Seafood allergies surprisingly common

Seafood allergies are far more common than previously thought and twice as prevalent as nut allergies in Americans.

As many as 1 in 50 American adults may have an allergy to seafood, a telephone survey of 15,000 adults has determined.

In conducting the survey, researchers at the Mount Sinai School of Medicine in New York also found that seafood allergies usually do not emerge until adulthood and can occur even in those with no history of allergies. They can trigger reactions on the skin -- such as hives -- in the gastrointestinal tract or, most seriously, in the respiratory tract.

More people are allergic to shellfish (1 in 50), with shrimp, crab and lobster causing more problems than fish (1 in 250). Some reactions are so severe they can make it difficult to breathe and require a quick shot of epinephrine to prevent death.

Women were more likely to report seafood allergies than men, though it was more common in boys than girls. African Americans reported a higher incidence than other races.

“Further studies are needed to determine the reason for women and minorities having a higher rate of seafood allergy, whether it is cultural eating differences, associations with environment exposures or other explanations,” study coauthor Dr. Scott Sicherer said. “What we do know is that seafood-allergic reactions may be potentially life threatening and should be taken very seriously, yet many of the participants did not seek proper diagnosis and treatment.”

The study appears in this month’s Journal of Allergy and Clinical Immunology.