Shellfish Allergy: Unmet Needs in Diagnosis and Treatment.

Seafood is a major cause of food allergy and anaphylaxis worldwide. Shellfish is included among the "big eight" food groups, which are responsible for more than 90% of all cases of food allergy. Approximately 2.5% of the world's population has experienced an adverse reaction to seafood. Seafood allergy is one of the most frequent and lethal allergies that exist. The several allergenic proteins involved in allergic reactions that have been described in recent years include tropomyosin, arginine kinase, myosin light chain, and sarcoplasmic calcium-binding protein. Despite all the data reported in the last few years, shellfish allergy is still diagnosed and treated as it was 50 years ago. The only effective treatment to prevent allergic reactions to shellfish is avoidance. This review aims to update recently published data on shellfish allergy and to highlight those areas that have yet to be resolved.

Lactobacillus Casei Zhang Alleviates Shrimp Tropomyosin-Induced Food Allergy by Switching Antibody Isotypes through the NF-κB-Dependent Immune Tolerance.

SCOPE: Shellfish allergy is an important cause of food allergy, and tropomyosin (TM) is the major allergen within shellfish. Probiotics are safe bacteria that benefit host health and nutrition and is proposed as a novel approach for treating immunological diseases, including food allergies. METHODS AND RESULTS: The probiotic strain Lactobacillus casei Zhang (LcZ) isolated from koumiss is investigated for its capacity to modulate food allergy induced by TM in BALB/c mice. Oral administration of LcZ attenuated allergy symptoms and intestinal epithelial damage. Furthermore, flow cytometry, real-time quantitative PCR, and ELISA demonstrated that LcZ administration altered the development and function of dendritic cells (DCs), T cells, and B cells, finally resulting in the change of TM-specific antibody isotypes into a tolerogenic pattern. Moreover, an in vitro spleen cell culture model reveals that LcZ directly modulates regulatory tolerogenic DC and T cell development, dependent on the activation of the nuclear factor kappa B (NF-κB) signaling pathway. CONCLUSION: This work indicates the ability of LcZ to alleviate TM-induced food allergy and demonstrates the involvement of the tolerogenic immune cells and NF-κB signaling pathway, indicating LcZ to be a potential immunomodulator and immunotherapy assistor.

An update on shellfish allergy.

PURPOSE OF REVIEW: Shellfish is an important cause of food allergy worldwide, and a major cause of food-triggered anaphylaxis. Despite the wide variety of shellfish, there is considerable serological and clinical cross-reactivity of major shellfish allergens, and accurate diagnosis remains a challenge in the management of shellfish allergy. RECENT FINDINGS: Novel minor allergens have been discovered and characterized, and advances in component resolved diagnostics have provided insights into the prevalence of sensitization and their clinical importance in shellfish allergy. The extensive cross-reactivity between tropomyosin of house-dust mite and crustacean shellfish has been postulated to be the cause of a proposed mite-shellfish oral allergy syndrome. SUMMARY: More studies in food challenge-proven patients are required to establish the true prevalence and natural history of shellfish allergy. Refinement of component resolved diagnostics and testing for minor allergens may be helpful in developing more precise species-specific tests. Further investigation into the role of tropomyosin in house-dust mite and shellfish allergies may provide novel immunotherapeutic approaches for shellfish allergy.

Allergic myocardial infarction: Type I Kounis syndrome following blue crab consumption.

Objectives: Allergic myocardial infarction, known as Kounis syndrome, is an acute myocardial infarction after an allergic reaction to food, drugs, or insect stings, etc. Kounis syndrome can also be caused by all kinds of seafood, such as finned fish, molluscan shellfish, cephalopods, and crustacean shellfish. Methods: Herein, we report a case of a 67-year-old man, with hypertension, referred for itchiness, facial rash, chest pain, and palpitations developed after consumption of blue crab. Results: Electrocardiogram showed ST elevations in leads II,III,aVF. Transthoracic echocardiography revealed inferior wall hypokinezia with a left ventricular ejection fraction of 55%. Coronary angiography revealed no sign of atherosclerosis. The patient was diagnosed to have Kounis Syndrome type I variant, secondary to blue crab ingestion. He was treated with oral antihistamines and prednisolone.The repeated cardiac markers were within normal limits, with resolution of electrocardiographic abnormalities and inferior wall motion echocardiographic changes. Conclusion: All patients admitted to the emergency department with chest pain and ST elevation on electrocardiography should be asked about allergic insults.