Introduction
People who suffer from an allergy to animal hair can have it in different forms. For some patients, it is enough that the corresponding animal is in the room for the symptoms to occur, for other patients the allergy only occurs in direct contact with the animal. Triggers of the allergy are however not the animal hairs themselves, but the proteins in the animal excrements, which settle in the fur of the animals.
These proteins usually come from the faeces, sweat, tallow or urine of the animals. Common animal hair allergies are directed against the proteins in the fur of dogs, cats, rabbits, and horses. The allergy can also occur in animals that have no hair in this sense, such as parrots and budgies. This is because these animals naturally also have excretions and the proteins stick in their plumage just as much as in the skins of rodents, for example. It is estimated that in Germany every 10th person is affected by an allergy to animal hair.
Origin
Basically, all allergies are the result of an overreaction of the immune system. Why it comes particularly in the industrial nations more frequently to the emergence of allergies, is until today not finally clarified. However there are different theories for the emergence of an (animal hair) allergy.
On the one hand, there are different classes of so-called immunoglobulins in the immune system, which mediate the immune system’s response. The immunoglobulin E (IgE) mediates not only the immune response in case of parasite infestation, but also in case of an allergy. Therefore the theory developed that due to the decrease of parasite infestations in industrialized countries, the immune system is “underemployed” and seeks a new kind of employment by forming an allergy.
The “hygiene hypothesis” also considers a kind of underemployment of the immune system. This hypothesis states that a very sterile environment, as is often the case in industrialized countries, promotes the development of an allergy. Since our environment is kept very clean and as free as possible from pathogens of a disease, our immune system looks for another task and overreacts on contact with the allergy causing substance (allergen).
As so often also the development of an animal hair allergy is connected with genetics, so the probability to fall ill with an animal hair allergy increases very strongly, as soon as both parents already suffer from an animal hair allergy. It has also been discussed whether vaccinating children can trigger an allergy, but several studies have been conducted and no evidence of an allergy associated with vaccinations has been found. The human body must also have had contact with the allergen in question before it can develop an allergy.
The immune system reacts neutrally to completely unknown substances at first contact. Only when the immune system has had the opportunity to “train” the immunoglobulins E (IgE) can they react to the allergen. If the instructed immunoglobulins E now encounter an allergen, they activate the scavenger cells (mast cells) of our body, these mast cells in turn release histamine and inflammation mediators. Thus, the same path is taken here as the body chooses in case of inflammation.