The issue of treatment of allergies is often complicated by the unwillingness of patients to isolate the source of their pathological condition – a pet. In some cases, this leads to the cooperation of an allergist and a veterinarian, together specialists can determine the nature of the allergen and figure out how to reduce its release to animals.
Such measures are effective in case of intolerance to the components of care products (shampoos, sprays), exoparasites or animal excreta – it is enough to cure a pet and minimize contact with excrement (cleaning trays).
In addition to eliminating contact with provocative antigens, the following therapeutic measures are distinguished:
- Antihistamine therapy. Antihistamines are widely used to reduce allergy symptoms. They can be administered in the form of tablets, eye or nasal drops and sprays during the period of exacerbation of the disease or as prophylaxis – for example, before intended contact with an animal.
- Desensitization therapy. With respect to a number of animal allergens, it is possible to use specific immunotherapy (ASIT) associated with the development of tolerance to a provoking protein substance. The essence of the technique is reduced to the introduction of small, gradually increasing dosages of the allergen over several months.
- Barrier techniques. Experimental methods based on the formation in the region of the nasal mucosa of the thinnest cellulose-based film or other compounds in nasal drops. As a result, the receipt of allergens in the tissue is complicated, manifestations of allergy are reduced. The techniques do not protect the skin or conjunctiva of the eyes, therefore, are used with a limited list of indications.
After making a diagnosis, in addition to avoiding contact with a pet, thorough cleaning of living quarters is necessary. Wet cleaning of floors, walls, furniture is made, carpets, upholstery and other fabric interior elements are carefully knocked out.
For some time, it is recommended to install filters for air purification, since the smallest scales of skin and lint can be kept in suspension even in the absence of dogs or cats.
Pet Allergies is a common condition, in recent years, more and more cases of the disease. This is due to the improvement of diagnostic methods and an increase in the number of pets in general – according to statistics, cats, dogs or other animals contain from 30 to 80% of families. Most often, the allergic state is registered in children, the disease can occur at any age and suddenly disappear after a certain period of time. According to some data, at least 15% of the total population of the Earth is subject to the development of pathology. A minor proportion of cases is represented by persons involved in agricultural work – caring for cows, goats, poultry. Epidemiology reflects the prevalence of contact with allergens – the incidence is higher in countries where more people keep pets.
Causes of Animal Allergies
The etiology of allergy is similar to other allergic conditions with contact or air transmission of a provoking substance (for example, pollinosis). For one reason or another, the patient has a perverted immunological reaction in response to the penetration of foreign substances of protein nature. In this pathology, the source of such compounds are domestic or, more rarely, farm animals.
Due to frequent and close contact with pets, allergies to them are characterized by a long chronic course, which can be complicated by other immunological conditions.
Provocative antigens may be contained in secretions:
- The elements of cover. Particles of wool, flakes of skin or feathers most often contain allergenic substances in their composition. Having a small size and light weight, they are able to be in the air for a long time, to penetrate into the respiratory tract. Pooh and wool can also be fixed in the fabric and pile of carpet – this explains the preservation of allergies, even after eliminating communication with animals.
- Exoparasites. Sometimes allergens are found in organisms parasitic on animal integuments (fleas, microscopic mites). Often this type of pathology occurs suddenly and disappears after treatment of the animal.
- Waste products. Feces or urine of some animal species may contain provoking substances. Most often, an allergy appears after cleansing trays, cells or terrariums and is limited to skin symptoms. Sometimes the appearance of allergens in the secretions associated with diseases of pets.
Various substances that make up shampoos, veterinary drugs, cell cleaners can also trigger allergic symptoms. Such a variant of the pathological condition may be mistakenly diagnosed as allergic to animals. Factors predisposing to the development of the disease are the presence of immunological disorders, other allergic conditions (for example, bronchial asthma), children’s age.
Violation of animal care contributes to the occurrence of pathology – the accumulation of potential allergens in large quantities can cause a reaction even in a healthy person. At the same time, contact with animals in early childhood (less than 2 years) reduces the risk of allergy in the future due to the development of immunological tolerance to certain antigens.
Pathogenesis of animal allergies
Despite the diversity of clinical manifestations, the reaction to allergens of domestic animals proceeds along the same pathogenetic pathway – immediate-type hypersensitivity reactions. At the first contact with the antigens of animal integuments, their parasites or secretions, the body becomes sensitized.
The provoking substances are recognized by the immune system, and class E antibodies (IgE) are formed against them. Immunoglobulins are absorbed on the surface of tissue basophil membranes (mast cells), making them susceptible to allergens. These cells play a central role in the further development of the pathological state.
At subsequent contacts, the binding of allergens to IgE, located on the membranes of basophils. This activates these immunocompetent cells and stimulates the process of their degranulation – the release of histamine, serotonin and prostaglandins into the intercellular space. These compounds contribute to the expansion of blood vessels and increase the volume of intercellular fluid, irritate sensitive nerve endings.
This is manifested by typical symptoms of allergy – redness, swelling of tissues, itching, discomfort, increased exudation of mucus or tears. Sometimes the amount of histamine released is so great that it leads to systemic reactions (anaphylactic shock) – a sharp drop in blood pressure, airway spasm.
Symptoms of Allergies in Animals
The manifestations of allergies are quite diverse, largely determined by the type of intolerance, the nature of the allergen and its distribution in the surrounding patient environment. In most cases, pet antigens spread through the air, easily penetrate into the upper respiratory tract and the conjunctiva of the eye. There is nasal congestion, tearing, sneezing, redness and itching of the eyes. Often, headaches and discomfort in the throat join these manifestations, sometimes hoarseness. In patients with asthma, there are possible attacks of bronchospasm 20-30 minutes after inhalation of air containing allergens.
In some patients, skin manifestations due to direct contact with animals or their metabolic products come to the fore. As a rule, the urticaria is detected in the area of skin contact with the provoking substance, sometimes it develops in other parts of the body. The duration of preservation of erythema, pruritus and other symptoms depends on the reactivity of the organism and the number of allergens in the environment.
Often there is a combined development of eye, respiratory and skin allergic manifestations. Some of them can occur in the form of contact dermatitis through a delayed-type hypersensitivity reaction (HRT), which is more often observed in persons caring for farm animals or employees of zoos.
In patients who have a strong sensitization to the antigens of animals, allergic symptoms may develop in the absence of direct contact. The main and most common allergens of cats (Fel d1 and Fel d2) and dogs (Can f1 and Can f2) are able to be transported through the clothes and other items of the owners. To highly sensitized individuals, such mediated contact is sufficient to develop a characteristic allergy symptom complex. The possibility of indirect interaction with provocative compounds is important to consider in the diagnosis of pathology.
Complications of animal allergies
Serious complications for this allergic state are not typical, however, the risk of their appearance increases with ignoring the symptoms of the disease and continuing contact with allergens. In individuals with asthma, the reaction can lead to severe bronchospasm and insufficient respiratory function.
Allergic nasoconjunctival syndrome can be complicated by a secondary bacterial infection of the mucous membranes, causing inflammatory purulent rhinitis or conjunctivitis.
In extremely rare cases, contact with animal antigens develops anaphylactic shock, which is a life-threatening condition. A long course of allergic rhinitis can provoke hyperplasia of the nasal mucosa and the appearance of polyps.
Diagnose Allergies in Animals
The identification of this condition in practical allergology requires the comparison of a large amount of anamnestic, clinical and laboratory data. This allows you to establish the relationship between the presence of a pet and the occurrence of pathological manifestations, and laboratory techniques provide an opportunity to confirm and clarify the diagnosis. Diagnosis can be difficult, since in some patients the symptom complex occurs some time after a cat or dog appears in the house.
Diagnosis of allergies is made according to the following algorithm:
- Survey and general inspection. On examination, characteristic non-specific manifestations of allergy are revealed – urticaria, conjunctival redness, tearing, complication of nasal breathing. When questioning is determined by the presence or absence of contact with animals during the last days and in previous periods. When interviewing the patient, it is also possible to determine the relationship between the symptoms and pets, and thereby adjust the plan for further diagnostic measures.
- Laboratory techniques. In general, blood tests usually show minimal changes – a slight increase in ESR, eosinophilia, and other signs of allergic inflammation. Specific tests reveal a significant increase in the level of type E immunoglobulins, which indicates an anaphylactic type of intolerance reaction.
- Allergological tests. The gold standard for diagnosing animal allergies is skin allergy testing – application, PIRM-test. Usually determine the body’s response to common allergens of dogs, cats, birds (depending on which animal the patient is in contact with).
Differential diagnosis is made with other types of allergic diseases (for example, pollinosis, intolerance to household dust), inflammatory pathologies of the mucous membranes (rhinitis, conjunctivitis).
The distinction between these states often becomes possible only after provocative allergological tests, which are the method of specific diagnostics.
Forecast and prevention of animal allergies
The prognosis of animal allergy is almost always favorable, only in individuals with a tendency to bronchial asthma, it worsens due to the risk of bronchospasm. Often the manifestations of the disease over time become less pronounced, even without serious therapeutic measures, so some patients prefer not to part with their pet, reducing the symptoms of allergy with antihistamines or agreeing to conduct ASIT.
Preventive measures help to reduce the concentration of animal allergens, reduce both the risk of occurrence and the severity of pathology. These include meticulous care of animals, the use of household air purifiers, washing hands after stroking or playing with a pet. It is important not to allow the animal on a chair or bed, especially in the bedroom, when traveling in a car, use special seat covers.