Allergy to pets: Causes

Generality

In susceptible people, contact with cats, dogs and other pets can trigger a violent hypersensitivity reaction of the immune system, which mainly affects the respiratory tract.

In particular, allergy to pets is triggered by "exposure to" all the protein components (allergens) contained in fallen hair, dead skin flakes, saliva or urine. Allergens, in fact, are microscopic and light particles, which spread easily in the air and remain in an environment for a long time; therefore, direct contact with the animal is not necessary. Indeed, those who are particularly sensitive can manifest an allergic reaction even when approaching people who have come into direct contact with an animal or when entering a room where it no longer stays. for months The "most" dangerous animal ", from this point of view, is the cat, since its saliva and dandruff contain a strong allergen; to follow, the dog and the horse. Occasionally, hamsters, guinea pigs, rabbits, poultry, cattle and pigs can also cause an immune response. However, it is necessary to consider that the pet is often a "fake allergen": it is not the contact with its hair, saliva or dandruff that causes the allergy, but the one with the mites that lurk in its fur. In this case, the animal is a simple vehicle of the real culprit. The allergy to pets manifests itself with symptoms typical of allergic rhinitis or asthma, such as dyspnoea and breathing difficulties, and can be associated with skin reactions (atopic dermatitis or urticaria) In the event of an allergy, the best strategy is to reduce exposure to the responsible allergens as much as possible. Medicines or other treatments may be needed to relieve symptoms and manage asthma.

Causes

Allergies occur when the immune system produces an excessive reaction against a foreign substance mistakenly perceived as harmful even if harmless to the body. Animal allergens are a series of protein components that, if inhaled or placed in contact with the skin of people particularly susceptible, they can trigger an allergic hypersensitivity reaction.

After exposure to the allergen, the immune system reacts by inducing an inflammatory process, which manifests itself with irritation of the upper airways and causes the typical symptoms of allergic rhinitis. Prolonged or regular exposure to the responsible allergen can cause a "Evolution of the allergic form into a" chronic inflammation associated with asthma. Any animal with fur can be a source of allergens, but allergies are often associated with cats and dogs.

Allergy to Cats and Dogs

Dog and cat allergens are mainly produced by the sebaceous and salivary glands and accumulate on the animal's skin. The most important allergic components are found in the fur and flakes of dead skin (dandruff), as well as being present in their saliva. , with which the mantle is cleaned, in the urine, in the faeces, in the tear fluid, in the sebum and in the sweat. Dandruff is a particular problem because it is made up of very small particles and can spread in the air for even long periods of time. It is also easily picked up by upholstered furniture and clothing. Saliva can stick to carpets, bedding, etc. furniture and clothing and, once dry, can be dispersed into very small particles that can cause allergic symptoms when inhaled into the upper respiratory tract (nose and sinuses) or into the lungs.

• The main allergen in cats is Fel d1, a protein molecule found mainly in dandruff, saliva, sebum, sweat and tear fluid. Cats often lick and, considering that the main source of allergens is found in the sebaceous glands, this operation helps to deposit and spread the substances responsible for the allergy. Cat allergens are one of the most important causes of respiratory allergy: they form a persistent aerosol that spreads to all parts of the house and seem to cause a predisposition to asthma. In particular, Fel d1, like other airborne allergens, is a component of the dust and, for this reason, it is extremely difficult to avoid exposure. The allergenic particles persist in the domestic environment even after 6 months from the removal of the animal (up to a maximum of four years). Furthermore, it must be borne in mind that these are very light and small in size: for this reason the allergenic components they are easily transported over great distances, as well as being able to penetrate deep into the respiratory tree. Curiously, the cat allergen has also been detected in Antarctica, where felines have never been present. All cat breeds have the potential to cause allergy. In addition, cross-reactions can occur with dogs, horses and pigs or with other felines.
• The dog allergy manifests itself less violently than the reaction triggered by felines and the allergenic load can vary between different breeds. The main source of allergens is represented by saliva, urine, sweat and products of the desquamation of the animal. The allergens Can f1 and Can f2 contaminate the hair, causing, following their dispersion in the air, manifestations such as rhinitis, conjunctivitis, asthma, urticaria and edema. Dog allergen particles are heavier than those of felines and, as a result, spread to a lesser extent. In the subject susceptible to Can f1 and Can f2, cross reactions with cat and horse may occur.

Allergy to rodents and rabbits

The rodents that make you most susceptible to allergic reactions are mice, gerbils, hamsters and guinea pigs. Allergens from rodents are usually found in hair, saliva and urine. The dust contained in the litter or in the sawdust on the bottom of the cages can contribute to spread the allergens present in the air. The urine contains, however, the allergen characteristic of hamsters and mice. The spread of these protein components on clothes or other objects it may be sufficient to trigger allergic rhinitis and asthma Rabbit allergens are instead present in hair and saliva, and represent a problem that particularly interests breeders.

Allergy to other animals

In the case of birds, it is the droppings, mites, pollen and substances that are deposited on the feathers that cause allergies. The horse is capable of triggering a severe hypersensitivity reaction, as it possesses very powerful allergens. Fortunately, quite close contact with the animal is required.

Allergy is rarely caused by animals that lack fur, such as fish and reptiles.