Bird allergy is a type of immunopathological process caused by the body’s hypersensitivity to components of bird feathers, scales, droppings or parasites. Symptoms depend on the reactivity of the body and the ways of penetration of the allergen – lacrimation, swelling of the mucous membranes of the nose, cough, possible development of urticaria, in rare cases – angioedema. The diagnosis is confirmed by conducting skin allergy tests, determining the level of specific immunoglobulins E in the blood. Treatment is carried out with the help of antihistamines, allergen-specific immunotherapy, elimination of the patient’s contact with allergen sources (domestic or ornamental birds).
ICD 10
J30.4 H10.1 J45.0
General information
The disease belongs to the group of household allergies, it also includes intolerance to household dust, animal hair and other allergens found in human habitation. Bird allergy can occur at any age, but is statistically more common in children. A similar condition develops in people working in close contact with birds and their processed products – employees of poultry farms, production facilities for the manufacture of down and feather products. In rural areas, the cause of the disease is more often agricultural varieties of birds, in the city – decorative (parrots, canaries).
Causes
Hypersensitivity develops as a result of sensitization of the body and subsequent re-entry of a specific antigen on the surface of the skin, mucous membranes of the conjunctiva or respiratory tract. There are the following types of allergens of avian origin:
- Scales of skin and feathers. Protein components of bird feathers and skin most often cause the development of the disease. They continuously flow from the animal’s integument into the external environment, saturating it with allergens.
- Components of the litter. The peculiarities of avian digestion are such that a large number of protein compounds (potential antigens) are released with droppings, which easily turn into an aerosol at the time of defecation. This contributes to their spread and facilitates their penetration into the human body.
- Waste products of parasites. A number of endo- and exoparasites of birds contain substances dangerous in terms of allergies. They can also enhance the release of feather scales and skin, spraying droppings, increasing the rate of penetration of irritating substances into the external environment.
Predisposing factors to the development of bird allergy are the characteristics of the reactivity of the body, genetic factors, immune disorders.
Pathogenesis
The first (anaphylactic) is involved in the development of bird allergy type of allergic reaction. At the first contact with an allergen, the body is sensitized – an increased sensitivity of the immune system to a specific antigen is formed. This corresponds to the usual immune response. During subsequent contacts with the antigen, the immunological reaction is distorted – instead of the characteristic immunoglobulins of classes G and M, lymphocytes secrete IgE. The latter stimulate receptors on tissue basophils (mast cells), which in the process of degranulation secrete biologically active substances (histamine, serotonin).
The secreted substances cause the expansion of arterioles, increase the permeability of the vascular wall and contribute to the development of tissue edema. With the local nature of the allergic reaction, pronounced manifestations are found in tissues directly in contact with the antigen. If you are allergic to birds, foreign protein substances enter through the respiratory tract, and some of the scales suspended in the air may fall on the conjunctiva of the eye. Therefore, rhinitis develops, nasal congestion, lacrimation and pain in the eyes. Antigens can get on the skin in direct contact with birds, causing urticaria – more often this form of the disease develops in children. In rare cases, allergens from feathers, bird droppings or parasites can cause systemic reactions and damage to the lower respiratory tract (alveolitis).
Symptoms
The manifestations of an allergic reaction are diverse and depend on the reactivity of the body, the ways of penetration of the allergen into the body, the age of the patient. Depending on the sensitization of the organism, from the moment of contact with birds or their waste products (fluff, droppings) to the development of the clinical picture of pathology, it may take from several minutes to 2-4 days. Common symptoms of the disease are nasal congestion, sneezing, rhinorrhea – manifestations of allergic rhinitis. Allergic conjunctivitis occurs, characterized by redness, lacrimation, itching of the eyelids.
When protein antigens penetrate into the nasopharynx, its swelling and inflammation occur – this is manifested by a feeling of tickling in the throat, dry cough, complaints of pain when swallowing. In children and persons with high reactivity of the body, the immunological condition is accompanied by a lesion of the lower respiratory tract – allergic bronchitis or alveolitis occurs. Their symptoms are debilitating dry or with the release of viscous thick sputum cough, wheezing in the lungs, difficulty breathing. Skin manifestations of the disease occur according to the type of urticaria with the development of redness and itching at the site of contact with the allergen, the appearance of blisters.
Bird allergy can occur acutely, characterized by a violent reaction of the body to contact with the antigen. Within a few minutes or hours, severe allergic rhinitis, conjunctivitis develop, with time there is a lesion of the lower respiratory tract. An increase in body temperature, muscle pain, and general malaise are recorded. With a subacute or chronic course, the symptoms of the disease are erased – patients complain of transient nasal congestion, frequent exacerbations of conjunctivitis, unexplained cough or periodic attacks of urticaria. With continued contact with the allergen, the course of pathology can last for months with a slow increase in the severity of symptoms.
Complications
Pronounced reactivity and severe intolerance to avian antigens can cause the development of angioedema, which threatens the patient’s life. With a less acute reaction, in case of prolonged contact with the source of the allergen, pronounced immunological disorders may occur – bronchial asthma, weakened immunity, and the occurrence of cross-allergy. There is a high probability of complications in the presence of pathologies in children whose immune system is in the process of formation. Allergic inflammation of the mucous membranes (rhinitis, conjunctivitis) can be complicated by secondary bacterial infection.
Diagnostics
The purpose of the diagnosis is to confirm the presence of an immunological disorder, to determine the group and type of allergen, to differentiate with other pathologies. Identification of bird allergy is based on the results of a number of studies:
- Expert consultations. The allergist examines the patient, preliminarily establishes the allergic nature of the lesion of the skin, mucous membranes and respiratory organs, collects the patient’s life history, forms a list of antigens based on the data obtained – possible causes of pathology. If necessary, the patient is referred for additional consultations to a dermatologist, an otolaryngologist, an ophthalmologist.
- Allergy tests (scarification and application tests, prick test, allergometric titration). With the help of skin allergy tests, the sensitivity of the patient to a number of antigens is checked during one procedure. The technique is highly specific and allows you to almost accurately determine the cause of the disease.
- Determination of the IdE level to individual allergens. The study determines the amount of class E immunoglobulins specific to this allergen in the blood serum. It is an even more highly sensitive method of allergy diagnosis than skin allergy tests, and often complements them. With the help of skin testing, a group of antigens causing intolerance is found out, and a colorimetric analysis of the IgE level reveals a specific allergen from this group.
For the diagnosis of pathology, auxiliary studies are also used – a general blood test, microscopic examination of sputum (with a productive cough). The blood picture is characterized by an increased level of eosinophils. Curschmann spirals and Charcot-Leyden crystals can be detected in sputum. Differential diagnosis is carried out with ornithosis and other types of household allergies (to wool, dust, mold fungi). Ornithosis is not characterized by damage to the upper respiratory tract (rhinitis, pharyngitis), but at the same time there is an increase in the liver and spleen, for the final confirmation of the diagnosis, the PCR method is used. Other types of allergies are easily excluded with the help of skin allergy tests.
Treatment of bird allergy
The central component of treatment in allergology is to limit and eliminate the patient’s contact with the source of the allergen. This is achieved by thorough wet cleaning of the premises, cleaning the dwelling from dust containing scales of bird feathers, skin or droppings, installing household air filters, airing the house or apartment. If the pathology is caused by intolerance to the antigens of parasites of ornamental birds (parrots, canaries), you can limit yourself to treating the animal with a veterinarian. These measures should be carried out in combination with drug therapy:
- ASIT. Allergen-specific immunotherapy requires precise determination of the allergen and is prescribed to individuals with relatively low immunological reactivity. Under the supervision of a doctor, the patient is injected with increasing dosages of the antigen that causes allergies, achieving a decrease in sensitivity to it. Such treatment in many patients has uncertain prospects.
- The use of antibodies to IdA. A type of immunotherapy that is based on the binding of IgE monoclonal antibodies, which reduces their amount in the blood. It is used for severe forms of allergies and bronchial asthma, provoked by allergens of bird feathers, down and skin. The drug from this group is omalizumab.
- Antihistamines. To reduce symptoms, medications that block H-1 histamine receptors are used. Antihistamines are used as part of drops for the nose, eyes and for oral administration in the form of syrups, tablets.
Complete elimination of contact with birds or their feathers, down, droppings is often enough for the symptoms of the disease to disappear spontaneously in 1-2 days without taking medications.
Prognosis and prevention
The disease is characterized by a relatively favorable prognosis for human life, but the duration of symptoms depends on how accurately the ban on contact with the source of allergy is carried out. In children with a long course of pathology, breathing problems may occur – prolonged nasal congestion leads to the development of a so-called “adenoid” face. There is also a threat of respiratory disorders due to chronic bronchitis, alveolitis or bronchial asthma. To prevent allergies to birds, you should contact him several times in a pet store or with friends before you get yourself an animal. The absence of negative reactions (nasal congestion, conjunctivitis, cough) indicates the normal sensitivity of the body. When keeping birds, it is necessary to regularly ventilate the room, clean the cages, and treat their parasitic diseases in a timely manner.
