shellfish allergy

Shellfish Allergy: A Common Food Allergy

A shellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals, including crustaceans and mollusks (1). This type of food allergy can cause a strong immune response, leading to various symptoms, ranging from mild to severe.

Common Symptoms

The symptoms of a shellfish allergy can occur within 60 minutes of eating the allergen and may include:

• Mouth and throat itching
• Lip swelling
• Skin reactions, such as hives, puffy eyes, and skin redness (5)
• Abdominal pain, diarrhea, nausea, vomiting, stomach cramps (8)
• Hives (allergic urticaria), itching, eczema (8)
• Wheezing, nasal congestion, coughing, hoarseness, throat tightness (7)

Severe Reactions

In some people, an allergic reaction to shellfish can be severe and potentially life-threatening, such as anaphylaxis (6). This is a medical emergency that requires immediate attention.

Prevalence

Shellfish allergies are a notable subset of food allergies and are particularly common among adults. According to Food Allergy Research & Education (FARE), over 6.5 million American adults have allergies to shellfish, making it one of the most prevalent adult-onset food allergies (11).

Diagnosis

To determine if you have a shellfish allergy, your healthcare provider will ask about your symptoms and perform a physical exam to rule out other medical problems (12). A history of allergic reactions shortly after exposure to shellfish can be a sign of shellfish allergy.

References:

(1) Shellfish allergy is an atypical response by the body's immune system to proteins in certain marine animals. (5) Symptoms of shellfish allergy include mouth and throat itching, lip swelling, skin reactions, such as hives, puffy eyes, and skin redness. (6) An allergic reaction to shellfish can be severe and potentially life-threatening, such as anaphylaxis. (7) Common symptoms of a shellfish allergy include wheezing, nasal congestion, coughing, hoarseness, throat tightness, belly pain, vomiting, diarrhea. (8) Symptoms of shellfish allergy include abdominal pain, diarrhea, nausea, vomiting, stomach cramps, hives (allergic urticaria), itching, eczema. (11) Shellfish allergies are a notable subset of food allergies and are particularly common among adults. (12) To determine if you have a shellfish allergy, your healthcare provider will ask about your symptoms and perform a physical exam to rule out other medical problems.

Shellfish Allergy Symptoms

A shellfish allergy can cause a range of symptoms, from mild to severe. Here are some common signs and symptoms:

• Mild symptoms: mouth and throat itching, lip swelling, skin reactions such as hives, puffy eyes, and skin redness [9]
• Moderate symptoms: atopic dermatitis (eczema), coughing or sneezing, coryza, circumoral paresthesias, nausea, diarrhea, vomiting, dizziness, and fainting [8]
• Severe symptoms: anaphylaxis, a life-threatening condition that can cause trouble breathing, constricted airways, vomiting, dizziness or fainting, and rapid heartbeat [4][6]

Timing of Symptoms

Symptoms typically occur within two to three hours of eating contaminated food [6]. In some cases, symptoms may be delayed.

Other Allergens

In addition to shellfish, other allergens such as tropomyosin, arginine kinase, myosin heavy chain, haemocyanin, and amylase have been identified in mollusks and crustaceans [7][10].

It's essential to note that a positive test result or skin test does not always indicate an allergic reaction. A negative test is more helpful to rule out a food allergy [2]. If you suspect a shellfish allergy, consult with your allergist for proper diagnosis and treatment.

References: [1] - Symptoms · Hives · Itchy, irritated skin · Nasal stuffiness (congestion) · Swelling of the lips, face, tongue and throat, or other parts of the ... [4] October 6, 2022 - In some people, an allergic reaction to shellfish can be severe and life-threatening – called anaphylaxis. Symptoms may include vomiting, dizziness or fainting and trouble breathing due to constricted airways. [6] April 29, 2024 - Symptoms occur within two to three hours of eating contaminated food, and consist of tingling of the lips, tongue and throat, often followed by stomach symptoms. [7] September 26, 2022 - Mild allergies manifest with pruritus ... symptoms associated with shellfish allergies are atopic dermatitis (eczema), coughing or sneezing, coryza, circumoral paresthesias, nausea, diarrhea, vomiting, dizziness, and fainting.... [8] Sep 20, 2024 — What are symptoms of shellfish allergy? · mouth and throat itching · lip swelling · skin reactions, such as hives, puffy eyes and skin redness. [9] September 26, 2022 - Mild allergies manifest with pruritus ... symptoms associated with shellfish allergies are atopic dermatitis (eczema), coughing or sneezing, coryza, circumoral paresthesias, nausea, diarrhea, vomiting, dizziness, and fainting.... [10] The Experts in Custom Signs. We've fulfilled signs all over the U.S. for millions of customers since 2005. Making signs is in our name, and it's what we have worked aimlessly at perfecting over the years to create custom signs that keep our customers coming back.

To diagnose a shellfish allergy, several tests can be performed.

• A thorough review of the patient's history is conducted to identify any previous reactions or allergies.
• A skin prick test is used to measure the body's reaction to specific allergens. This test involves pricking the skin with a small amount of the suspected allergen and observing for any reaction, such as redness, itching, or swelling [1].
• Blood tests can also be performed to measure the levels of IgE antibodies in the blood. These antibodies are produced by the immune system in response to an allergen and can indicate the presence of a shellfish allergy [2][3].

It's worth noting that while these tests can help diagnose a shellfish allergy, they are not always 100% accurate. A negative test result does not necessarily rule out a food allergy, as the tests may not detect all possible allergens [4].

Current Treatment Options for Shellfish Allergy

Shellfish allergy, like other food allergies, has no specific treatment to cure it. However, there are some treatments that can help manage the symptoms and prevent severe reactions.

• Epinephrine (EpiPen): This is the first-line treatment for anaphylaxis, a severe whole-body allergic reaction that causes symptoms such as tightening of the airway [8]. Epinephrine auto-injectors are often carried by individuals with shellfish allergy in case of accidental exposure.
• Oral Immunotherapy (OIT): This is a type of treatment where small amounts of the allergenic food, in this case, shellfish, are introduced to the body under medical supervision. The goal is to desensitize the individual and reduce their allergic reaction [6].
• Anti-inflammatory drugs: Corticosteroids and anti-IgE medications like omalizumab can be used alone or in combination with OIT to manage symptoms and prevent severe reactions [3][9].

New Developments

Recently, a new medication called Xolair has been approved by the FDA for reducing allergic reactions to more than one type of food after accidental exposure [7]. This is a significant development in the treatment of shellfish allergy.

It's essential to note that while these treatments can help manage symptoms and prevent severe reactions, they are not a cure for shellfish allergy. Individuals with this condition must still take precautions to avoid exposure to shellfish and be prepared to administer epinephrine if necessary.

References:

[3] October 6, 2022 - A combination of probiotics and ... of allergen-specific immunotherapy. [6] February 12, 2024 - In the event of a serious allergic ... will likely provide an epinephrine auto-injector to deliver adrenaline during a reaction. [7] Feb 16, 2024 — Xolair is the first FDA-approved medication to reduce allergic reactions to more than one type of food after accidental exposure. [8] April 13, 2022 - Shellfish is among the most common food allergens. But all food allergies can be dangerous. Epinephrine is the first-line treatment for anaphylaxis, a severe whole-body allergic reaction that causes symptoms, including tightening of the airway. [9] Oct 6, 2022 — Anti-inflammatory drugs (such as corticosteroids) and anti-IgE (like omalizumab) are mainstream nonspecific treatments that can be used alone or ...

Differential Diagnosis of Shellfish Allergy

Shellfish allergy can be challenging to diagnose, and it's essential to consider other conditions that may present similar symptoms. Here are some differential diagnoses for shellfish allergy:

• Bacterial gastroenteritis: This condition can cause symptoms such as nausea, vomiting, diarrhea, and abdominal pain, which may be mistaken for a shellfish allergy.
• Celiac disease: An autoimmune disorder that causes the immune system to react to gluten, leading to symptoms like abdominal pain, diarrhea, and fatigue. These symptoms may be similar to those experienced in a shellfish allergy.
• Chronic gastritis: Inflammation of the stomach lining can cause symptoms such as abdominal pain, nausea, and vomiting, which may be confused with a shellfish allergy.
• Constipation: While not typically associated with food allergies, constipation can cause abdominal discomfort and bloating, which may be mistaken for a shellfish allergy.
• Diverticulitis: A condition where small pouches in the digestive tract become inflamed, leading to symptoms like abdominal pain, fever, and changes in bowel habits. These symptoms may be similar to those experienced in a shellfish allergy.

Other conditions to consider

• Scombroid poisoning: A type of food poisoning caused by consuming spoiled fish or shellfish, which can lead to symptoms such as hives, itching, and swelling.
• Anisakis: A parasitic infection that can cause symptoms like abdominal pain, diarrhea, and weight loss.

Key points to remember

• Shellfish allergy is a specific condition that requires careful diagnosis and treatment.
• Other conditions may present similar symptoms, making differential diagnosis crucial for accurate diagnosis and treatment.
• A thorough medical history and physical examination are essential in diagnosing shellfish allergy and ruling out other conditions.

References:

[1] by LL Alonso · 2022 · Cited by 5 — Differential Diagnosis [3] Jul 2, 2024 — Shellfish is a common food allergy. Some people with shellfish allergy react to all shellfish, while others react to only certain kinds. [8] by SH Sicherer · Cited by 2 — DIFFERENTIAL DIAGNOSIS · Scombroid poisoning · - Diagnosis · Other types of seafood poisoning · Anisakis · Allergy ... Symptoms and signs of ... [5] by CK Woo · 2011 · Cited by 98 — In addition to the above specific five types of shellfish toxicity, the differential diagnosis should include bacterial toxins, viral and bacterial infections.