Update on the bird-egg syndrome and genuine poultry meat allergy.

Allergy to poultry meat is rare and affects both children and adults. The prevalence of poultry meat allergy is unknown, but presumably is similar to that of red meat allergy. There is no close relationship between allergy to poultry meat and allergy to red meat. Poultry meat allergy may present as primary (genuine) food allergy or as secondary food allergy resulting from cross-reactivity. Secondary poultry meat allergy may arise in the context of bird-egg-syndrome, which is due to sensitization to serum albumins present in many tissues including muscle tissue and egg yolk (Gal d 5). Primary sensitization to serum albumin may happen via the respiratory tract through exposure to pet birds (mainly in adults) or within the context of egg allergy in early childhood. Due to the heat lability of serum albumins, reactions are often limited to the skin upon contact with raw meat. Symptoms from meat ingestion are rare and mostly mild, whereas systemic reactions are common after ingestion of raw or soft-boiled egg yolk. Primary poultry meat allergy is mainly seen in adolescents and young adults, though hypersensitivity may have started already at (pre)school age. Egg allergy is usually absent. Typical symptoms of primary poultry meat allergy include OAS (±dyspnea), gastrointestinal complaints, urticaria and angioedema. Severe anaphylaxis with cardiovascular symptoms is rare. Chicken and turkey meat are highly cross-reactive and responsible for most reactions, while duck and goose meat causes milder or no symptoms. Soups, sausages, and ham represent relevant allergen sources, too. Patients with poultry meat allergy unexpectedly often suffer from concomitant allergy to fish and possibly shrimp. Serum specific IgE against fish and shrimp is found in respectively 60 and 40 % of sera, suggestive of cross-reactive allergens in these foods. The allergens thus far recognized in genuine poultry meat are LMW proteins of 5-25 kDa. One of them has been identified as α-parvalbumin cross-reactive with homologous mammal α-parvalbumins but not with fish α-parvalbumins. Recently, myosin light chains, including 23 kDa MLC-1 (Gal d 7) and 15 kDa MLC-3, have been recognized as new major allergens in chicken meat. The high similarity of chicken MLCs with those from various fish species (∼65 %) might explain the clinical association of poultry meat allergy with fish allergy.

Síndrome ave-huevo / Bird-egg syndrome

Antecedentes. Se ha descripto una relación entre la hipersensibilidad respiratoria tipo I frente a antígenos aviares y la alergia alimentaria a la yema de huevo. Dicha asociación se denomina síndrome ave-huevo, y el responsable de dicho cuadro es la alfa-livetina o seroalbúmina de pollo, un antígeno presente tanto en la yema del huevo como en las plumas, suero y excrementos de las aves. Materiales y métodos. Estudiamos una paciente con síntomas de alergia alimentaria tras la ingesta de huevo, quien además sufría de síntomas respiratorios (rinitis/asma) causados por la exposición a aves. Se realizaron pruebas cutáneas con huevo, alfa-livetina, pollo crudo y cocido, y plumas. La IgE sérica específica fue identificada por técnica de microarrays de alérgenos (Immuno CAP ISAC). Resultados. Los prick test fueron positivos para alfa-livetina (8 mm), pollo crudo (8 mm) y plumas de gallina (7 mm). La determinación de IgE sérica específica fue de 16,61 (kU/l) para alfa­livetina. Conclusiones. El síndrome ave-huevo es producido por la sensibilización a la alfa livetina, un alérgeno que puede actuar tanto por vía alimentaria como por vía inhalatoria. Según nuestro conocimiento, es el primer caso diagnosticado a través de la técnica de microarray de alérgenos.(AU)

Background: A relationship between type I hypersensitivity with respiratory symptoms due to bird antigens and allergy to egg yolk has been described. This association is known as bird-egg syndrome, which is caused by sensitization to chicken serum albumin (alpha-livetin), present in bird feathers and serum, and egg yolk. Material and methods: We studied one patient with food allergy to egg yolk who also suffered from respiratory symptoms (rhinitis- asthma) caused by exposure to birds. Sensitization to egg yolk and bird antigens was investigated by skin prick test. Specific IgE was investigated using allergens Microarrays (Immuno CAP ISAC). Results:Our patient had a positive skin prick test to: chicken serum albumin (alpha livetin): 8 mm, bird feathers: 7 mm, raw chicken: 8 mm. Specific IgE to alpha livetin was 16.61 (kU/l). Conclusions: Bird-egg syndrome is due to a sensitization to alpha-livetin, an allergen that can act either on the respiratory or the digestive way. In our knowledgement, this is the first case described using allergen Microarrays technique.(AU)