Poultry meat is popular worldwide as a protein source with high nutritive value. The United States (US) are the largest poultry meat producer in the world. Gallus gallus domesticus (red jungle fowl) is native to Asia and domesticated worldwide. Poultry meat allergy is rare, with worldwide prevalence ranging from 0-13%. Main route of exposure is reported to be oral (ingestion of meat) and secondary route of exposure includes inhalation (vapor during cooking) or skin contact. The allergy is triggered within 30 mins of exposure, and allergic reaction includes oral symptoms and moderate systemic reactions in skin and gastrointestinal tract including urticaria, angioedema, nausea, emesis, diarrhea, and asthma. Cardiovascular symptoms in case of severe anaphylaxis is rare.

Allergen identified in poultry meat are Gal d 5 (Serum albumin), Gal d 7 (Myosin light chain kinase), Gal d 8 (α-parvalbumin), Gal d 9 (β-enolase), and Gal d 10. Among these, Gal d 5, 7 and 8 are the major allergens responsible for allergic reactions and cross reactivity in sensitized individuals. Chicken and turkey meat are reported to be highly cross reactive and responsible for majority of allergic reactions. Diagnosis of poultry meat allergy can be done with total IgE assay or Basophil Activation Test (to identify specific allergen). An allergic patient should avoid the exposure to the poultry meat in order to prevent the trigger of allergic reaction.

Nature

Globally chicken is the most popular poultry used for both meat and egg production. Poultry products have high nutritive values (major protein source) (1). Poultry meat contains a low amount of fat, high-quality proteins, vitamins, and micronutrients(2).

Habitat

Chickens are habituated in the company of human beings (1). The United States is the largest poultry meat producer. (2).

Taxonomy

Worldwide distribution

Poultry meat allergy is regarded as a rare disease (2). A study by Inam et al. (2016) included 689 adult allergic patients from Rawalpindi and Islamabad in Pakistan, and the results estimated a 7% prevalence of chicken meat allergy among the given population. The result was similar to the previously reported worldwide prevalence of chicken allergy of 0-13% (3).

Risk factors

Poultry allergy is reported to be triggered by skin contact, or inhalation of vapors during cooking poultry meat (2).

Worldwide distribution

Red jungle fowl (Gallus gallus species) is commonly found in India, China, Java, Malaysia, Indonesia and the Philippines. Also, sub-species Gallus gallus domesticus originated in Asia and then domesticated worldwide (1).

Main

The main route of exposure to chicken meat allergen is ingestion and the heat resistant meat allergen enters the intestinal mucosa (4).

Secondary

Vapors inhaled and skin contact during cooking poultry meat (2).

Other diseases

Poultry meat allergy can be categorized as primary (genuine) food allergy and as secondary food allergy occurring due to cross-reactivity.  The reaction to primary (genuine) poultry meat allergy usually starts within 30 minutes and this occurs due to the sensitization of heat-resistant meat allergen in the intestinal mucosa. Mostly the adolescents and young adults show this type of allergy (4). Primary poultry allergy symptoms are:

• Contact reactions and oral allergy syndrome- severe reactions correlated to breathing problems.
• Regular systemic reactions - moderate in severity and confined to the skin and the gastrointestinal tract (GI tract) including urticaria, angioedema, nausea, emesis, diarrhea, and asthma.
• Cardiovascular symptoms are rarely reported during severe anaphylaxis (4).

In a case study of a 54-year-old patient with severe allergic reactions to poultry products within few minutes of chicken or turkey meat or chicken broth ingestion, the reported allergic reactions included swelling of the tongue, oral mucosa, vomiting and hypotension. However, the patient tolerated chicken eggs (5). Another case study reported a 20-year-old man who had experienced oropharyngeal and palmar itching, facial hives, lip swelling, dysphagia, dyspnea, and heartburn 15 minutes after eating chicken. The individual tolerated turkey and did not have any other poultry meats or meats including veal, pork, and rabbit. Also, he tolerated eggs and reported no contact with birds (6).  

In-vitro diagnostic tests for IgE-mediated allergic disease are:

• Total IgE assay – It is a nonspecific test and provides  general information about allergy
• Serum specific IgE (sIgE) assays against allergen sources – This is a commonly used diagnostic test for the identification of allergen
• Basophil Activation Test (BAT) – It’s a specific test to identify a causative allergen, however, the test is quite complex in its execution (7). 

Prevention strategies

Avoidance

To avoid food allergy the basic step is to avoid food ingredients that cause allergic reactions. Always read the composition of the products given on the labels (8). 

Allergenic molecules

Important allergens identified in chicken meat are Gal d 5 (Serum albumin), Gal d 7 (Myosin light chain kinase), Gal d 8 (α-parvalbumin), Gal d 9 (β-enolase), Gal d 10 (Aldolase)(8). Among these allergenic molecules,  Gallus domesticus 5 or Gal d 5  which is a serum albumin is categorized as the major allergen, responsible for secondary chicken meat allergy (2). Gal d 8 (α-parvalbumin is one of the important and the earliest allergens identified which has  high thermal stability and resistance to protein digestion (4, 9). Gal d 7 (Myosin light chains 1) is also a major allergen in poultry meat. They are small proteins with various isoforms and with molecular weight ranging from 16 to24 kDa (4).  

Biomarkers of severity

Diagnosis of patients primarily sensitized to poultry meat can be done by using recombinant Gal d 7 (2).

Cross-reactivity

Gal d 5, is the major allergen and cross-reactivity of chicken meat with other avian meats and egg yolk is due to this allergen (Hemmer, Klug et al. 2016). A study by Kuehn et al. (2016) evaluated the importance of clinical cross-reactivity among fish and chicken meat in patients (n = 29) allergic to fish and chicken meat or only to chicken meat (n = 7). The study detected cross reactivity among fish and chicken meat. Patients allergic to fish and chicken meat may develop a food allergy to chicken meat or fish, respectively. Hence, known as “fish–chicken syndrome” and parvalbumins, enolases, and aldolases are identified as major cross-reactive allergens (9). One previous case study reported about cross reactivity of chicken Gal d 8 (α-parvalbumin) with similar homologs from pig, horse and cattle(5). Cross reactivity of various avian serum albumin and intake of raw or soft-boiled egg yolk triggers oral and GI allergic reactions along with mild to moderate systemic reactions. Also, poultry meat allergy has close relationship with fish and shellfish allergy because these foods contain cross-reactive homologous allergens. Chicken and turkey meat are highly cross-reactive. Gal d 7, a  heat-resistant major allergen in chicken meat shows intense cross reactivity with homologous proteins from turkey, goose, and duck (4). 

Other topics

Primary and secondary poultry meat allergies

• Primary (genuine) poultry meat allergy: It is caused due to heat resistant meat allergen via ingestion through oral route and is not associated with allergy to egg.
• Secondary poultry meat allergy: It is related to ubiquitous serum albumins sensitivity which may have occurred either through inhalation when exposed to birds (bird-egg syndrome) or through exposure to egg yolk in children (egg-bird syndrome). Bird-egg syndrome (secondary poultry meat allergy) has a similarity with cat-pork syndrome which occurs due to primary inhalant sensitization to mammalian serum albumin via exposure to furry animals (4).

Author: Turacoz Healthcare Solutions

Reviewer: Dr. Fabio Iachetti

Last reviewed: October  2020