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If you develop a skin rash after eating shrimp, you are most likely experiencing a type of food allergy. Shellfish allergies are one of the most common food allergies. Shrimp are a type of shellfish, a marine animal with a shell. Shellfish include both mollusks and crustaceans, such as clams, oysters, abalone, squid, shrimp, crab and lobster. Developing a skin rash is one of the first signs of an allergic reaction and is not to be ignored. If you suspect you may have an allergy to shrimp or other foods, contact your health care provider. There are tests available to confirm this allergy.

How It Occurs

Any allergy to any food begins with an abnormal immune response. Certain proteins in shrimp are wrongfully recognized by your body's immune system as being harmful. This triggers an immune system response to release antibodies to attack the protein, called tropomyosin, according to the University of Nebraska-Lincoln. The next time you are exposed to the shrimp protein, your immune system releases histamine, the substance responsible for development of the skin rash and other symptoms.

Symptoms

An allergic reaction can cause a skin rash within minutes up to a few hours after eating the shrimp. Your reaction to the shrimp can vary; milder symptoms include developing a skin rash and itching. If you have a stronger reaction, you can develop other symptoms including hives and swelling of the face, lips, mouth and tongue. If you are highly allergic, you may also begin to wheeze and feel like your throat is closing, making it difficult to breathe or swallow. This is a serious situation that requires immediate medical attention. If you develop a skin rash after eating shrimp, do not eat it again until you have confirmed the allergy. Allergic reactions can become progressively worse after each exposure.

Severe Reaction

Shrimp and other food allergies are the number one cause of anaphylaxis, a severe allergic reaction. MedlinePlus states anaphylaxis is a life-threatening, whole body reaction to the allergen, causing widespread release of histamine from all the body's tissues. Symptoms develop very rapidly and include abdominal cramps, confusion, slurred speech, extreme wheezing , difficulty breathing, vomiting, diarrhea, rapid heartbeat and fainting. If not treated immediately, anaphylaxis can lead to coma and death. This is a medical emergency that requires 911 support.

Precautions

Once you develop a skin rash after eating shrimp, you will probably have the allergy your entire life. It's crucial that you avoid any contact with shrimp or shrimp products. Read all food product labels, which must state if they contain shellfish. You must ask detailed questions when you eat out, especially at seafood restaurants; you will need to know what foods are prepared in proximity to the shrimp. You should also wear a medical alert bracelet stating you are allergic to shrimp. Antihistamines will calm a skin rash and hives, but you will need an injection of epinephrine to reverse a severe reaction. Talk to your doctor; if your allergy is severe, you may need to carry injectable epinephrine.