Belonging to arthropod family, crustacean is among most commonly used sea foods. Divided into six sub groups, it contains more than 44000 species that are used extensively or less extensively. Crab, crayfish and lobster are among those Crustacean family members that are more likely to be eaten by the human beings. Crustacean allergy can cause wide range of problems. From itching and swelling of lips, mouth, throat and tongue, the crustacean allergy can cause problem up to difficulty in breathing, dropping of blood pressure and even death.