Generality
Pet allergies are a common cause of dry throat, conjunctivitis, rhinitis, asthma and skin reactions.
Most sensitization occurs against cats, dogs, horses and rodents. Skin and blood tests allow us to ascertain the susceptibility to a specific allergen and to quantify the extent of the manifestations it can induce. The patient may suffer an allergic reaction even when he does not have pets; in fact, contact with animal allergens carried by other people is sufficient: microscopic and light particles are deposited on clothes, hair or under the sole of shoes, to then spread easily in the environment, settle in the dust or remain suspended in the air. Allergens can thus be inhaled, penetrate the respiratory system and cause an immune reaction in hypersensitive individuals.
Treatment
The first line of treatment against allergic reactions caused by pets is to avoid exposure to allergens as much as possible; in this way the symptoms should manifest themselves with a lower frequency or intensity. However, it is extremely difficult to avoid such exposure, because, even if you do not have a pet, you can unexpectedly come into contact with allergens present in the environment or on people and objects. Moreover, the allergy to the cat or the dog is perennial and does not respect a seasonality. For these reasons, it may be necessary to use some drugs to control the symptoms or to prevent them .
Symptomatic Treatments
Your doctor may directly indicate one of the following medications to improve respiratory symptoms:
- Antihistamines reduce the production of histamine, a chemical produced in response to particular stimuli of the immune system and active in an allergic reaction. As a result, these drugs help relieve symptoms such as itching, recurrent sneezing and a runny nose. Antihistamines are available as nasal sprays, tablets or syrups for children (for example: fexofenadine, loratadine and cetirizine).
- Corticosteroids taken as nasal sprays can reduce the symptoms associated with inflammation and control the symptoms of allergic rhinitis. These drugs include fluticasone, mometasone furoate, triamcinolone and ciclesonide. Corticosteroids applied topically by nasal route allow a low dose of medication to be used and produce fewer side effects than oral corticosteroids, sometimes necessary for severe attacks.
- Decongestant nasal sprays can be used to provide rapid relief of rhinitis symptoms, for example by helping to reduce swelling in the nasal cavities or making breathing easier. However, the effect on allergy symptoms is temporary and, by using a decongestant spray for more than three consecutive days, the worsening of nasal congestion can be encouraged. Decongestants taken by mouth can increase blood pressure and should not be taken if you suffer from high blood pressure, glaucoma or cardiovascular disease. For these reasons, it is advisable to resort to the help of decongestants only after consultation with your doctor.
- Sodium cromoglicate (as well as other cromoni) prevents the release by the immune system of histamine and other chemical mediators involved in the allergic reaction; in this way it reduces symptoms and inflammation in the airways. Local application (nasal spray) may be necessary several times a day and is more effective if it occurs before signs and symptoms develop. Chromones tend to be more effective in mild cases of asthma. Sodium cromoglicate is usually well tolerated and has no serious side effects.
- Antileucotrienes block the action of certain chemicals in the immune system. In fact, leukotrienes are compounds released by cells during an inflammatory response and exert a powerful constrictive effect on the airways. Antileucotriene drugs, taken orally (example: montelukast), play an antagonistic action with respect to these molecules and relieve allergy symptoms. Antileucotrienes may be prescribed if the patient is unable to tolerate nasal sprays based on corticosteroids or antihistamines. Possible side effects of antileucotrienes include upper respiratory tract infection, headache and fever. Less common side effects include mood changes, such as anxiety or depression.
- Eye symptoms may include eye drops containing sodium chromoglycate or antihistamines to reduce redness, itching and inflammation (allergic conjunctivitis).
Immunotherapy and anti-asthmatics
Immunotherapy
The results of the tests performed in the diagnostic phase can favor the development of a desensitization treatment for the specific allergen. This "vaccine" can "train" the immune system to gradually lose its hypersensitivity to the substance that triggers the pet allergy.
The immunotherapeutic protocol provides exposure to minimal doses of allergen, in this case the animal protein that causes the allergic reaction. These doses are gradually increased, usually during 3-6 months. The subsequent maintenance phase consists of taking a dose of the preparation for at least 3-5 consecutive years.
Immunotherapy is usually used when other treatments are not effective. The desensitization treatment has the potential to significantly reduce allergy to pets, until it disappears; however, the patient's adherence to treatment must be particularly careful and constant.
In case of Asthma
If the allergic reaction can induce asthma crises, in addition to the symptomatic drugs (corticosteroids, chromones and leukotriene receptor antagonists) the doctor may prescribe bronchodilator drugs. In case of respiratory difficulties, these act on the smooth muscles of the airways, dilating and rendering them pervasive, thus improving the flow of oxygen. Bronchodilators are available on prescription and can be used with the utmost caution, as they can cause serious side effects.
The most used are:
- Beta-2 agonists: they can relax and make the airways open, making breathing easier. These drugs can be fast-acting (example: salbutamol) or long-term (salmeterol and formoterol). The former should be used for sudden crises, as they act within about 5 minutes of their inhalation, while the latter are suitable for chronic cases. The action of beta-2 agonists can last about 12 hours, making them suitable for a double daily intake.
- Anticholinergics : they are less effective than the previous ones, but have fewer side effects. They are used especially in cases of mild asthma.
- Theophylline and derivatives: these drugs are less commonly indicated, as they can produce rather pronounced side effects, such as nausea, vomiting and headache.
