There are two components to whether you can--and should-sue.The first is liability, or legal obligation/responsibility to pay. This is based on fault, which depends typically on either an intentional bad act or negligence (unreasoanble carelessness). Since an allergy to shrimp is not an uncommon one, mislabeling shrimp as chicken is very likely unreasonably careless, since it exposes dinner to unnecessary danger and yet is easily correctable. Therefore, there may be liability.The second issue is damages; the American legal system, except in special cases usually involving deliberate bad acts, only provides compensation for actual injury and out-of-pocket costs. If you did not have extensive medical costs and recovered within a day or three, and did not miss much work, then it is unlikely your damages, or the amount of money you could receive, would be sufficient to justify the cost of a lawsuit. You may wish instead to contact the central office, let them know what happened and that you are contemplating a lawsuit, and see if they offer you any compensation.