The most common symptoms of shrimp or prawn allergy is itching and localized swelling of the mouth. Sometimes small itchy bumps might develop on the tongue, lips and inside lining of the cheeks. Other more generalized symptoms include urticaria (hives), throat swelling, sneezing, runny nose and wheezing. The most severe symptom would be anaphylaxis (allergic shock).
If a person is diagnosed with shrimp/prawn allergy, it is best to avoid all shellfish and see an Allergist as soon as possible for a full evaluation. The table below displays how the shellfish family is divided.
However, it is possible for someone with shrimp/prawn allergy to tolerate eating other shellfish. If the person is allergic to shrimp/prawn but eats cuttlefish or squid without any problems, then there is no need to avoid the food that is tolerated.
Based on publish medical literature, the odds for someone who has shrimp/prawn allergy; the chance of having allergy to other species in the crustacea family is around 40%. The chance for having allergy to species in the mollusks family is lower at 15%.
The major allergen in shellfish is tropomyosin. And majority of patients with shellfish allergy develop an IgE antibody towards tropomyosin. It is still not entirely known why a person can be allergic to one species of shellfish and not others, perhaps these individuals are sensitized to only a specific allergen found in that specific shellfish.
If a person who has shrimp/prawn allergy truly desires to eat other members of the shellfish family, evaluation by a qualified Allergy and Immunology specialist with an Oral Food Challenge can help determine what can be safely eaten.
So if a person has shellfish allergy:
- It is important for the person to have an Epipen available at all times.
- Read labels of food and be aware of cross contamination of served food with shellfish that is cooked in vicinity.
- Understand that a person might be allergic to one family of shellfish and not the other but this should only be evaluated by an Allergist.