Parrots are a group of colorful tropical bird species popular as pet birds. Most parrot species are found in tropical and sub-tropical forests across Central and South America, Australasia, Oceania, and Africa. Parrots are found to nest in holes and prefer to reside in wetter environments and warm regions. Some parrot blooms are found to be responsible for transporting soluble antigens to the lower airways and, therefore, can act as an adjuvant, enhancing the immunogenic reaction. Exposure to parrot feathers has been found to be associated with the bird-egg syndrome, asthma, allergic rhinitis, rhinoconjunctivitis, and hypersensitivity pneumonitis. Studies with parrot feather extract have reported the presence of few allergenic protein bands. Cross-reactivity is found between sera and feathers of bird species, including parrots, the canary, goose, hen, duck, and pigeon. Furthermore, budgerigar feather extract (containing albumin) is reported to be cross-reactive with egg yolk extract (containing Gal d 5).

Worldwide distribution

In a study from an allergic population in Venezuela, serum specific-IgE (sIgE) to parrot feathers were observed in 24 out of 189 allergic patients with allergic rhinitis and/or asthma (6).

Occupational allergy to birds has been reported as one of the significant health issues among zoo bird keepers, which was addressed in a study involving Polish zoo employees (Swiderska-Kielbik, Krakowiak et al. 2011). The study assessed 200 bird zookeepers where allergen-sIgE against any bird allergen was found in 72 % of subjects, and sIgE against parrot feathers was detected among 25 % of the subjects (7)

Living environment

Parrots nest in holes and prefer to reside in wetter environments and warm regions (3, 8).

Worldwide distribution

Most parrot species are found in tropical and sub-tropical forests across Central and South America, Australasia and Oceania, and Africa (9).

Main

Inhalation of parrot feathers dust is considered the route of exposure that can trigger immunological reactions (5, 10).

Allergy to parrots has been reported to be associated with rhinoconjunctivitis, asthma, allergic rhinitis, bird-egg syndrome, and bird fancier’s lung (11-15).

Asthma, allergic rhinitis, and rhinoconjunctivitis 

Bronchial asthma, allergic rhinitis, and rhinoconjunctivitis may result from exposure to budgerigar feathers, serum, or droppings (11, 15). 

Bird-egg syndrome

Bird-egg syndrome (typically based upon sensitization to bird allergens and allergic symptoms occurring after egg consumption) has been reported in adults due to sensitization to avian airborne allergens through feathers, sera, and droppings of pet birds, including parrots (12). 

Bird fancier’s lung 

Bird fancier’s lung is a common type of hypersensitivity pneumonitis triggered by frequent exposure to avian aeroantigens (including proteins present on the feathers and excreted in bird droppings) (13, 14).

In a study involving patients with bird fancier’s asthma, the highest sIgE antibody binding was observed among bird fanciers (the bird caregivers) who had contact with the feathers of the bird species, including parrots (10).

Prevention strategies

Avoidance

Completely avoiding the antigen source is considered the primary measure to reduce the amount of antigen in the respiratory system (12, 16). Additionally, patients are also suggested to thoroughly clean their house and install HEPA air cleaner (17).

Allergenic molecules

To date (22-SEP-2021), no allergenic molecule has been identified from parrot feathers according to the WHO/IUIS (18).

However, a study has found well-defined major allergenic bands (through IgE immunoblots; 20-30 kDa and 67 kDa) with feather extracts and serum proteins of parrot, budgerigar, canary, pigeon, and hen (10).

Furthermore, another study found a 70 kDa allergenic protein band (based on IgE immunoblotting) with budgerigar (parrot) feather extract corresponding to the budgerigar serum albumin (12).

Cross-reactivity

Cross-reactivity was seen between sera and feathers of the tested bird species (including the parrot, canary, goose, hen, duck, and pigeon) in patients with bird fancier’s asthma (10).

Cross-reactivity was seen between egg yolk extract (Gal d 5; livetin) and budgerigar feather extract containing albumin (12).

Author:Turacoz Healthcare Solutions

Reviewer: Dr. Christian Fischer

Last reviewed: March  2022