Summary

The common carp (Cyprinus carpio) is among the most widely cultivated freshwater fish globally, valued for its economic significance and adaptability. It has two primary forms: C. carpio morpha hungaricus, characterized by an elongated body, and C. carpio morpha acuminatus, which has a shorter, compact build and a pronounced shoulder. Fish allergies are reported in 0.2% to 2.29% of the general population, with prevalence reaching up to 8% among fish processing workers due to occupational exposure. The allergenic potential of common carp primarily arises from beta-parvalbumin, a calcium-binding protein abundant in the muscles of bony fish. Clinical symptoms of carp allergies include urticaria, angioedema, gastrointestinal issues, respiratory distress, and, in severe cases, anaphylaxis. Exposure to carp allergens occurs primarily through ingestion but may also result from inhaling aerosolized proteins during cooking or processing, and as direct skin contact while handling fish. Testing for sensitization typically involves skin prick tests and specific IgE testing. Avoidance remains the primary strategy for managing fish allergies.

Epidemiology

Worldwide distribution

The prevalence of self-reported fish allergy ranges from 0.2% to 2.29% in the general population, rising to as much as 8% among fish processing workers. The common carp is among the most widely eaten and extensively farmed fish species and is known to cause allergy symptoms in individuals sensitized to fish. A multicenter cross-sectional observational clinical survey on fish allergy involving 56 patients was conducted across six allergy centers in Italy. Among these participants, 67.8% tested positive for the single beta-parvalbumin Cyp c 1. Overall, 92.8% of the patients tested positive for at least one beta-parvalbumin. Another study included 26 patients (both children and adults) with confirmed fish allergies from Greece, the Netherlands, and Spain. Patients were identified based on detailed case histories and confirmed positive specific IgE levels. In 73% of the patients’ sera, IgE-binding activities were found to be comparable between purified natural and recombinant beta-parvalbumins from cod and recombinant beta-parvalbumin from carp.

Risk factors

Genetic and environmental factors, both prenatal and postnatal, have been identified as significant risk factors for food allergies. Research highlights the role of heredity in the development of atopy and the production of IgE. Moreover, fish sensitization can occur through damaged skin barriers in individuals with pre-existing atopy and hand eczema. Delaying the introduction of complementary foods has also been associated with an elevated risk of developing allergies.

Pediatric issues

A cross-sectional telephonic survey conducted across the USA revealed that the prevalence of fish allergies is significantly lower in children in comparison to adults, with rates of 0.2% and 0.5%, respectively. In a study conducted in Hong Kong, 69 participants with physician-diagnosed IgE-mediated grass carp allergy, aged 2 to 16 years, were recruited from all four pediatric allergy referral centers in the region. The study focused on examining the molecular characteristics of grass carp parvalbumin Cten i 1 and its allergenicity. Among the allergens tested, IgE reactivity was highest for Cten i 1, followed by Cyp c 1 (common carp) and Gad m 1 (cod). A study conducted in Luxembourg included 18 patients with fish allergies (mean age 16 years) and 7 control subjects to assess clinical reactivity to a cartilaginous fish (ray fish) and IgE responses to parvalbumins from both bony and cartilaginous fish. Positive reactions to at least one parvalbumin were observed in 78% of the allergic individuals, all of whom demonstrated sensitivity to beta-parvalbumins.

Route Of Exposure

Main

The primary pathway of fish sensitization is through ingestion via the gastrointestinal tract, where allergens interact with the intestinal epithelium.

Secondary

The secondary route of exposure involves inhalation of fish proteins, which is particularly relevant in both domestic and occupational environments. Patients with fish allergies may react to aerosolized proteins released during the cooking or processing of fish. Additionally, allergen exposure can occur through skin contact while handling and preparing fish.

Clinical Relevance

The most common hypersensitive reaction to fish is IgE-mediated. Patients sensitive to one or multiple fish species may experience symptoms such as vomiting, urticaria, diarrhea, and coughing. Clinical symptoms of allergy may differ based on the cooking method used, eating habits, and the type of fish consumed, potentially affecting the respiratory, skin, and digestive systems. Fish allergies can also cause severe reactions, including anaphylactic shock in certain cases.

Cutaneous and gastrointestinal symptoms

In a study, 68 patients tested positive for the common carp allergen (Cyp c 1) and presented clinical symptoms such as angioedema, contact urticaria, erythema, gastrointestinal issues, and oral reactions.

Anaphylaxis and respiratory symptoms

The common carp allergen has also been associated with anaphylaxis and respiratory symptoms.

Diagnostics

The existing clinical approaches to diagnosing fish allergies are clinical assessment, specific IgE testing, skin prick test (SPT) and oral food challenge. An accurate diagnosis requires a detailed history of the allergic episode, including information on the timing, duration, type, and quantity of fish consumed, as well as symptoms affecting the skin, mucous membranes, cardiovascular, respiratory, and neurological systems. Accurate diagnosis should consider the fish species commonly consumed in specific geographic regions. For instance, while various species of carp are widely eaten in some parts of Asia, they are not considered among the most frequently eaten fish in the USA and Europe.

Prevention And Therapy

Avoidance

Avoidance of fish is strongly recommended for individuals with fish allergies. Allergen specific immunotherapy is currently not available.

Cross-Reactivity

Cyp c1, the carp beta-parvalbumin, is the major fish allergen and exhibits broad cross-reactivity among most fish species. The parvalbumin isoforms Cyp c 1.0101 and Cyp c 1.0201 from common carp showed the highest sequence homology with other bony fish species, such as silver hake, toadfish, whiting, chub, Atlantic salmon, and pike. Similarly, the 9 kDa parvalbumin (Cten i 1) from grass carp was found to exhibit a high amino acid sequence homology (91.7%) with Cyp c 1. Parvalbumins from sharks and various bony fish species (carp, cod, and salmon), share amino acid sequence homology of less than 50%. A high sequence identity has been observed between bony fish parvalbumins and muscle parvalbumins from amphibians, birds, and reptiles.

Explained Results

Allergen Information

The common carp is one of the most widely consumed and extensively farmed fish species, recognized for its potential to trigger allergic reactions in sensitized individuals. Two allergens have been identified in carp: Cyp c 1 (beta-parvalbumin) and Cyp c 2 (beta-enolase), with beta-parvalbumin being the major allergen. Carp muscle tissue contains a high concentration of parvalbumin, reaching up to 5 mg per gram.

Clinical information

Fish allergies, primarily IgE-mediated, can cause symptoms such as urticaria, gastrointestinal issues, respiratory distress, and, in severe cases, anaphylaxis. Reactions may vary based on the type of fish and its preparation methods. The common carp allergens, particularly Cyp c1, has been linked to angioedema, contact urticaria, erythema, gastrointestinal issues, oral reactions, and respiratory symptoms. Notably, a documented case reported anaphylaxis triggered by cutaneous exposure to cyprinids.

Cross-reactivity

Cyp c1, the carp beta-parvalbumin, is the primary allergen and demonstrates extensive IgE cross-reactivity with parvalbumins from various fish species, including salmon, cod, and mackerel. Studies have also revealed significant amino acid sequence homologies between carp parvalbumins and those from other fish, amphibians, reptiles, and birds. Author: Turacoz Reviewer: Dr. Michael Spangfort Agabriel, C., P. Robert, P. Bongrand, J. Sarles and J. Vitte (2010). "Fish allergy: in Cyp c1 we trust." Allergy 65: 1483-1484. Barakov, R., S. Nurtazin, S. Sharakhmetov, S. Pueppke, N. Graham, K. Isbekov and I. Galymzhanov (2024). "Biological and ecological characteristics of common carp (Cyprinus carpio Linnaeus, 1758) in Kapchagay Reservoir, Kazakhstan." Egypt J Aquat Res 50: 400-407. De Aramburu Mera, T., S. Cimbollek, F. Pineda De La Losa and M. Castillo Fernandez (2020). "Allergy to Black Bass Fin and Carp." J Investig Allergol Clin Immunol 30: 193-194. Dickel, H., A. Kuehn, B. Dickel, A. Bauer, D. Becker, M. Fartasch, M. Haeberle, S. M. John, V. Mahler, C. Skudlik, E. Weisshaar, T. Werfel, J. Geier and T. L. Diepgen (2021). "Assessment of the effects of a work-related allergy to seafood on the reduction of earning capacity in the context of BK No. 5101." Allergol Select 5: 33-44. Dijkema, D., J. A. M. Emons, A. Van de Ven and J. N. G. Oude Elberink (2022). "Fish Allergy: Fishing for Novel Diagnostic and Therapeutic Options." Clin Rev Allergy Immunol 62: 64-71. FAO. (2024). "Common carp - Cyprinus carpio." Retrieved November 18, 2024, from https://www.fao.org/fishery/affris/species-profiles/common-carp/common-carp-home/en/. Jonsson, K., M. Barman, H. K. Brekke, B. Hesselmar, S. Johansen, A. S. Sandberg and A. E. Wold (2017). "Late introduction of fish and eggs is associated with increased risk of allergy development - results from the FARMFLORA birth cohort." Food Nutr Res 61: 1393306. Kalic, T., F. Morel-Codreanu, C. Radauer, T. Ruethers, A. C. Taki, I. Swoboda, C. Hilger, K. Hoffmann-Sommergruber, M. Ollert, C. Hafner, A. L. Lopata, M. Morisset, H. Breiteneder and A. Kuehn (2019). "Patients Allergic to Fish Tolerate Ray Based on the Low Allergenicity of Its Parvalbumin." J Allergy Clin Immunol Pract 7: 500-508. Kalic, T., C. Radauer, A. L. Lopata, H. Breiteneder and C. Hafner (2021). "Fish Allergy Around the World-Precise Diagnosis to Facilitate Patient Management." Front Allergy 2: 732178. Kaza, U., A. Knight and S. Bahna (2007). "Risk Factors for the Development of Food Allergy." Curr Allergy Asthma Rep 7: 182-186. Klueber, J., D. Schrama, P. Rodrigues, H. Dickel and A. Kuehn (2019). "Fish Allergy Management: From Component-Resolved Diagnosis to Unmet Diagnostic Needs." Curr Treat Options Allergy 6: 322-337. Kuehn, A., T. Scheuermann, C. Hilger and F. Hentges (2010). "Important variations in parvalbumin content in common fish species: a factor possibly contributing to variable allergenicity." Int Arch Allergy Immunol 153: 359-366. Lee, P. W., J. A. Nordlee, S. J. Koppelman, J. L. Baumert and S. L. Taylor (2012). "Measuring parvalbumin levels in fish muscle tissue: relevance of muscle locations and storage conditions." Food Chem 135: 502-507. Leung, N. Y. H., A. S. Y. Leung, K. J. Y. Xu, C. Y. Y. Wai, C. Y. Lam, G. W. K. Wong and T. F. Leung (2020). "Molecular and immunological characterization of grass carp (Ctenopharyngodon idella) parvalbumin Cten i 1: A major fish allergen in Hong Kong." Pediatr Allergy Immunol 31: 792-804. Ma, Y., U. Griesmeier, M. Susani, C. Radauer, P. Briza, A. Erler, M. Bublin, S. Alessandri, M. Himly, S. Vazquez-Cortes, I. R. de Arellano, E. Vassilopoulou, P. Saxoni-Papageorgiou, A. C. Knulst, M. Fernandez-Rivas, K. Hoffmann-Sommergruber and H. Breiteneder (2008). "Comparison of natural and recombinant forms of the major fish allergen parvalbumin from cod and carp." Mol Nutr Food Res 52: S196-207. Mastrorilli, C., S. Arasi, S. Barni, D. Caimmi, F. Chiera, P. Comberiati, G. Dinardo, A. Giannetti, M. Gismondi, S. Gracci, F. Paravati, U. Pelosi, M. Miraglia Del Giudice, R. Bernardini and L. Pecoraro (2023). "IgE-Mediated and Non-IgE-Mediated Fish Allergy in Pediatric Age: A Holistic Approach-A Consensus by Diagnostic Commission of the Italian Society of Pediatric Allergy and Immunology." Medicina (Kaunas) 59. Mukherjee, S., P. Horka, K. Zdenkova and E. Cermakova (2023). "Parvalbumin: A Major Fish Allergen and a Forensically Relevant Marker." Genes (Basel) 14. NCBI. (2020). "Cyprinus carpio." Retrieved November 18, 2024, from https://www.ncbi.nlm.nih.gov/datasets/taxonomy/tree/?taxon=7962. Perez-Tavarez, R., H. Moreno, J. Borderias, D. Loli-Ausejo, M. Pedrosa, J. Hurtado, R. Rodriguez-Perez and M. Gasset (2021). "Fish muscle processing into seafood products reduces β-parvalbumin allergenicity " Food Chem 364: 130-308. Sharp, M. F. and A. L. Lopata (2014). "Fish allergy: in review." Clin Rev Allergy Immunol 46: 258-271. Sicherer, S. H., A. Munoz-Furlong and H. A. Sampson (2004). "Prevalence of seafood allergy in the United States determined by a random telephone survey." J Allergy Clin Immunol 114: 159-165. Sližienė, A., M. Plečkaitytė, M. Zaveckas, K. Juškaitė, V. Rudokas, G. Žvirblis and A. Žvirblienė (2022). "Monoclonal antibodies against the newly identified allergen β-enolase from common carp (Cyprinus carpio)." Food Agri Immunol 33: 129-149. Stephen, J. N., M. F. Sharp, T. Ruethers, A. Taki, D. E. Campbell and A. L. Lopata (2017). "Allergenicity of bony and cartilaginous fish - molecular and immunological properties." Clin Exp Allergy 47: 300-312. Swoboda, I., A. Bugajska-Schretter, P. Verdino, W. Keller, W. R. Sperr, P. Valent, R. Valenta and S. Spitzauer (2002). "Recombinant carp parvalbumin, the major cross-reactive fish allergen: a tool for diagnosis and therapy of fish allergy." J Immunol 168: 4576-4584. Villalta, D., E. Scala, G. Deleonardi, M. Busa, F. Rivolta, E. Boni, G. Gabrielli, L. Farioli, C. Cappelletti, F. Buzzulini, M. Conte, V. Pravettoni and R. Asero (2022). "A comprehensive molecular approach in fish allergy: Usefulness in daily clinical practice." Clin Chim Acta 533: 104-108. WHO/IUIS. (2019). "Cyp c 1." Retrieved 26 November, 2024, from https://www.allergen.org/viewallergen.php?aid=781. WHO/IUIS. (2020). "Cyp c 2." Retrieved 26 November, 2024, from https://www.allergen.org/viewallergen.php?aid=1045.