Although there is no reliable information demonstrating the chances of developing an allergic reaction to fish oil supplements if you're allergic to shellfish, MedlinePlus recommends avoiding its use. Shellfish are a common food allergy that can lead to a severe allergic reaction, anaphylaxis. If you have been diagnosed with a shellfish allergy, you need to talk with your doctor before taking a fish oil supplement. There is a risk of having an allergic reaction to the fish oil supplement.
A shellfish allergy is one of the most common food allergies. It forms in childhood, but isn't typically detected until adulthood because most children don't eat shellfish, according to MayoClinic.com. Shellfish include shrimp, crab, oysters, lobster and any other fish that is in a shell. Most symptoms of a shellfish allergy are mild, but they can be severe. The allergic reaction is related to the proteins found in the flesh of the shellfish, which the immune system overreacts to, causing common allergy symptoms.
Fish oil does not contain the proteins from the flesh of the shellfish, but can have traces of tiny molecules of the proteins, according to the Food Allergy Initiative. Because there is a chance of developing an allergic reaction, you should avoid the use of fish oil supplements. Fish oil supplements are typically used to increase your daily intake of omega-3 fatty acids. You can use other omega-3 supplements that do not contain fish by-products, such as vegetable or flax seed oils.
If you take fish oil supplements and begin to develop common shellfish allergy symptoms, discontinue use of the supplement and call your health-care provider. The most common symptoms from a shellfish allergy include: hives, eczema, itching, abdominal pain, nausea, vomiting, diarrhea, swelling of the face, throat, tongue, tingling, dizziness, fainting, wheezing, trouble breathing and nasal congestion. Any symptoms that develop need to be disclosed to your doctor.
If you've been diagnosed with a severe shellfish allergy, do not take fish oil supplements. Talk to your doctor about receiving a prescription for an epinephrine pen, in case of an emergency. An epinephrine pen is a drug that is injected if you accidentally consume shellfish by-products, and it can save your life. Severe allergic reaction symptoms include: facial swelling, hives, shortness of breath, lightheadedness, dizziness and a rapid heart rate. Call 911 for emergency medical attention if these symptoms develop.