Allergy to Shellfish
Shellfish, or crustaceans are generally cross reactive. If one is allergic to one, one should try to avoid all of them.
The list of includes:
Fish are not included in this group.
Anyone with shellfish allergy, however, should be cautious, because fish and shellfish may be processed together.
For more on the Prevalence of Seafood Allergy in the United States visit this National Institutes of Health website