Symptoms
A cat allergy manifests itself similarly to hay fever. Possible symptoms include an allergic rhinitis, sneezing, coughing, asthma, shortness of breath, wheezing, allergic conjunctivitis, eye watering, hives, dermatitis, rash when scratching, and itching. Complications include the development of asthma and chronic sinusitis. Patients often suffer from other allergies.
Causes
The cause is type 1 hypersensitivity to cat allergens, of which Fel d 1 is considered the most important (85-95%). It is a heat-resistant protein from the sebaceous and salivary glands of cat skin, consisting of two subunits. It enters the environment on very small particles in the micrometer range, can remain airborne for a very long time, and can settle on clothes, surfaces, walls, upholstery groups, mattresses, carpets, and curtains. Fel d 1 is formed mainly on the cat’s face, and the skin and fur are the reservoirs. Cat allergy is therefore not an actual cat hair allergy. The allergens are widely distributed in the environment. They are found not only in the homes of cat owners, but even in places where no cat has ever lived and in public places, such as day care centers, schools, movie theaters, public transportation, and hospitals. Clothing, in particular, is considered an important vector of Fel d 1. A room where a cat used to reside may still be contaminated to a degree sufficient to cause sensitization or trigger an acute allergic reaction. Interestingly, children who grow up with a cat are less likely to develop allergy than children without a pet. Moderate allergen exposure is thought to be more dangerous than high exposure.
Diagnosis
Diagnosis is made by medical treatment including an epicutaneous test, based on clinical symptoms, and a blood test. Other conditions such as hay fever, asthma, or a cold must be ruled out.
Nonpharmacologic treatment
One approach is to avoid the allergens. However, because of their ubiquitous distribution, this proves difficult, and it is nearly impossible to remove all allergens from a contaminated room. However, it has been shown that consistent cleaning can reduce the concentration. The cat can be kept if desired and depending on the symptoms, some habituation may be possible. In this case, however, it is important to take appropriate measures. Separation from the cat is often difficult, but may be necessary.
- Keep the living quarters very clean, regularly clean and damp pick up, including walls.
- Remove carpets and replace them with easy-to-clean surface, such as parquet or panels
- Replace upholstered furniture
- Clean bedding regularly, special mattresses or pads.
- Air purification with HEPA filter
- Ventilate frequently
- Special vacuum cleaner with HEPA filter
- Wash clothes frequently
- Wash cat regularly (difficult…)
- Establish cat-free zones in the house, including the bedroom and living room.
- Let cat outside often
Drug treatment
The following antiallergic drugs are used for drug prevention and treatment: 2nd generation antihistamines such as cetirizine (Zyrtec, generic), fexofenadine (Telfast, generic), and loratadine (Claritine, generic) are taken as tablets and are effective for up to 24 hours. Possible adverse effects include drowsiness. Antihistamines may also be administered locally as nasal sprays or eye drops. Glucocorticoids are preferably used locally, as nasal sprays for allergic rhinitis and nasal congestion, as eye drops for severe allergic conjunctivitis, and as inhalation for asthma and bronchitis. Systemic therapy is indicated only in a severe course. Decongestant nasal sprays with active ingredients such as xylometazoline (Otrivin, generics) and oxymetazoline (Nasivin, generics) should be used only exceptionally for nasal symptoms because they cause rhinitis medicamentosa with regular use. Beta2-sympathomimetics such as salbutamol (Ventolin, generic) relax the bronchi and facilitate breathing. Common adverse effects include trembling of the hands and palpitations.Mast cell stabilizers such as cromoglicic acid inhibit the release of histamine and other inflammatory mediators and are used preventively. Leukotriene antagonists such as montelukast (Singulair, generics) are anti-inflammatory and anti-allergic and are administered orally. Nasal irrigation with seawater or salt water can remove allergens from the nasal cavities and improve nasal symptoms. Specific immunotherapy can be used to desensitize patients diagnosed with allergy. This involves regular injections of the allergens under the skin over a period of months.
