Pigeon allergy in asthmatics: An update

Abstract

Asthma is a chronic airway illness characterized by obstruction to airflow, bronchial hyperreactivity, underlying inflammation, and variable and recurrent symptoms. In different geographical areas, the prevalence of asthma varies from 1% to 18%, affecting around 300 million people worldwide.[1] Asthma prevalence in adults and children in India ranges from 0.96%–11.03% to 2.3%–11.9%, respectively.[2] Sensitization to specific allergens such as house dust mites, animal dander, cockroaches, or molds is a major risk factor for asthma, according to several studies.[3] Asthma symptoms frequently worsen when these allergens and allergic persons contact, as a result of the immune systems attacking the allergens. One of the most prevalent domestic and urban birds is the pigeon. Pigeons and doves belong to the Columbiformes order and the Columbidae family. A pigeon subspecies that evolved from the rock dove is known as the domestic pigeon (Columba livia domestica or Columba livia forma domestica).[4] The oldest domesticated bird in the world is the rock pigeon. According to research, pigeons were domesticated as early as 10,000 years ago.[5] Pigeon fancying is one of the oldest human traditions, and it is currently a well-liked vocation everywhere in the world. Pigeon feeding is also a very widespread hobby. It has long been known that people who keep pigeons are extremely close to them and are more likely to acquire allergies, including pigeon-breeder's lung, rhinitis, and asthma.[6] With due respect to the religious-minded person, we do not hurt the sentiments of any person. This is just a scientific finding. Pigeon droppings and feathers are a significant source of allergens that are known to cause allergic reactions in people with diseases of the airways such as hypersensitivity pneumonitis (HP), asthma, and others.[6] Both city birds and avian pets frequently include pigeons. Pigeon interactions with people have expanded as a result of continuous urbanization and industry, which has boosted their population in cities. Pigeon feathers and droppings have demonstrated potential as sources of sensitizing allergens, which can trigger an allergic reaction.[7,8] HP is frequently brought on by exposure to pigeon feathers and droppings. Pigeon-breeder's disease, also known as occupational lung disease, is a well-known case of immune complex-mediated hypersensitivity brought on by exposure to pigeon antigens at work.[9,10] Recent research from India demonstrates that even without a history of occupational exposure, HP is one of the common kinds of interstitial lung disease.[11] In another investigation, 17 out of 108 individuals who had previously been exposed to pigeons were shown to have positive skin prick test results for pigeon allergens. Only 2 (11.8%) patients had a lower serum MUC1 level, whereas the level was greater or upregulated in 15 (88.2%) patients against pigeon antigens.[12] Previous studies have shown that asthma patients with various bird-related HP or who are allergic to pigeon allergens (droppings and feathers) have greater serum KL-6 levels than the general population.[12,13] In a study of 270 pigeon fanciers for the incidence of simple chronic bronchitis in relation to avian exposure and immunoglobulin G antibody to pigeon sensitization, Bourke etal. expressed their opinions. They discovered that despite never having smoked in their lives and having no other lung conditions, 26.2% of pigeon enthusiasts had uncomplicated chronic bronchitis.[14] In a study of 500 asthmatics, Deo etal. came to the conclusion that 17% of the asthmatics had pigeon antigen reactivity, which may be contributing to an increase in asthma cases in their city.[15] Asthma incidence in the inner city could increase. A similar study found that 15.7% of asthma patients who had been exposed to pigeons had pigeon allergen sensitivity.[16] To effectively control their asthma, asthmatic patients should avoid unnecessary exposure to pigeon antigens. In our country, feeding pigeons is considered a cultural and religious obligation. This can be one of the causes of the rise in asthma cases in Indian cities. To effectively control the condition, we advise asthmatic patients to avoid unnecessarily being exposed to pigeon antigens.