Shellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include:  Hives Itchy, irritated skin Nasal stuffiness (congestion) Swelling of the lips, face, tongue and throat, or other parts of the body Wheezing or trouble breathing Coughing and choking or a tight feeling in the throat Belly (abdominal) pain, diarrhea, nausea or vomiting Dizziness, lightheadedness or fainting  Anaphylaxis Allergies can cause a severe, potentially life-threatening allergic reaction known as anaphylaxis. It can occur within seconds to minutes after exposure to something you're allergic to ⸺ and worsens quickly. An anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal. Anaphylaxis causes the immune system to release a flood of chemicals that can cause you to go into shock. Signs and symptoms of anaphylaxis include:  A swollen throat or tongue or a tightness in the throat (airway constriction) that makes it difficult for you to breathe Coughing, choking or wheezing with trouble breathing Shock, with a severe drop in your blood pressure and a rapid or weak pulse Severe skin rash, hives, itching or swelling Nausea, vomiting or diarrhea Dizziness, lightheadedness or fainting 
shellfish allergy symptoms generally start minutes hour eating contact shellfish  may include:  hives itchy  irritated skin nasal stuffiness (congestion) swelling lips  face  tongue throat  parts body wheezing trouble breathing coughing choking tight feeling throat belly (abdominal) pain  diarrhea  nausea vomiting dizziness  lightheadedness fainting  anaphylaxis allergies can cause severe  potentially life-threatening allergic reaction known anaphylaxis  can occur seconds minutes exposure you're allergic ⸺ worsens quickly  anaphylactic reaction shellfish medical emergency  anaphylaxis requires treatment epinephrine (adrenaline) injection follow-up trip emergency room  anaphylaxis isn't treated right away  can fatal  anaphylaxis causes immune system release flood chemicals can cause shock  signs symptoms anaphylaxis include:  swollen throat tongue tightness throat (airway constriction) makes difficult breathe coughing  choking wheezing trouble breathing shock  severe drop blood pressure rapid weak pulse severe skin rash  hives  itching swelling nausea  vomiting diarrhea dizziness  lightheadedness fainting 
shellfish allergy