Allergic rhinitis is caused by an allergic reaction to an allergen, such as pollen, dust and certain animals.
If you have allergic rhinitis, your immune system your natural defence against infection and illnesswill react to an allergen as if it were harmful.
If your immune system is oversensitive, it will react to allergens by producing antibodies to fight them off. Antibodies are special proteins in the blood that are usually produced to fight viruses and infections.
Allergic reactions don't occur the first time you come into contact with an allergen. The immune system has to recognise and "memorise" it before producing antibodies to fightit. This process isknown as sensitisation.
After you develop sensitivity to an allergen, it will be detected by antibodies called immunoglobulin E (IgE)wheneverit comes into contact with the inside of your nose and throat.
These antibodies cause cells to release a number of chemicals, including histamine, which can causethe inside layer of your nose (the mucous membrane) to become inflamed and produce excess mucus. This is what causes the typical symptoms of sneezing and a blocked or runny nose.
Allergic rhinitis is triggered by breathing in tiny particles of allergens. The most common airborne allergens that cause rhinitis are described below.
House dust mites are tiny insects that feed on the dead flakes of human skin. They can be found in mattresses, carpets, soft furniture, pillows and beds.
Rhinitis isn't caused by the dust mites themselves, but bya chemical found in their excrement. Dust mitesare present all year round, although their numbers tend to peak during the winter.
Tiny particles of pollen produced by trees and grasses can sometimes cause allergic rhinitis. Most trees pollinatefrom early to mid-spring, whereas grasses pollinate at the end of spring and beginning of summer.
Rhinitis can also be caused by spores produced by mould and fungi.
Many people are allergic to animals, such as cats and dogs. The allergic reaction isn't caused by animal fur, but flakes of dead animal skin andtheir urine and saliva.
Dogs and cats are the most common culprits, although some people are affected by horses, cattle, rabbits and rodents, such as guinea pigs and hamsters.
However,being around dogs from an early age can help protect against allergies, and there's some evidence to suggest that this might also be the case with cats.
Some people are affected by allergens found in their work environment, such as wood dust, flour dust or latex.
It isn't fully understood why some people become oversensitive to allergens, although you're more likely to develop an allergyif there's a history of allergies in your family.
If this is the case, you're said to be "atopic", or to have "atopy". People who are atopichave a genetic tendency to develop allergic conditions. Their increased immune response to allergens results in increased production of IgE antibodies.
Environmental factors may also play apart. Studies have shown certain things mayincrease the chance of a child developing allergies, such as growing up in a house where people smoke and being exposed todust mites at a young age.
<p><strong>Allergic rhinitis is an inflammation of the inner nose which is caused by allergens, such as flower pollen, dust or animal hairs. </strong></p><p><strong>Many individuals suffer from this condition, hence it is very common. Allergic rhinitis is associated with similar symptoms to the common cold, such as sneezing, a congested, dry nose, itching etc. In some individuals these symptoms are mild, and in others they are more severe and present at all times. In some patients, symptoms are present all year round, whereas for others, they only appear seasonally. </strong></p><p> </p>
<p><strong>Allergic rhinitis is caused by an allergic reaction which occurs in the human body when it falls in contact with an allergen, which may be dust, flower pollen, animal hair etc. The allergens trigger the onset of several symptoms. Our natural immune systems interpret the presence of allergens as they would the presence of an infectious agent, and hence the immune response to allergens is the same response that your body would organize against a bacterium or virus. People who are highly sensitive to allergens produce antibodies against them. Several common allergens include:</strong></p><p><strong>1. Common house dust (in linens, carpets and other household items)</strong></p><p><strong>2. Flower pollen (usually in spring and autumn)</strong></p><p><strong>3. Remnants from domestic animals (dogs, cats, horses, rabbits), which include hair, urine, spit etc. </strong></p><p><strong>People with a family history for allergies are more likely to develop allergic rhinitis. </strong></p><p> </p><p> </p>
<p><strong>After inquiring for a thorough family history of the patient, the doctor may order the following tests:</strong></p><p><strong>1. Scratch test (the arm is scratched with a needle containing an allergen, and the skin is observed for any subsequent development of a rash).</strong></p><p><strong>2. A blood test to measure for the levels of IGE immunoglobulins, which are elevated in case of an allergic reaction. Another indicator is the elevated level of eusinophiles. </strong></p><p><strong>3. In cases when the condition concurrs with another condition, (like for example nasal polyps or sinusitis), other examinations are required, such as : nasal endoscopy, or a nose scanner. </strong></p><p> </p>
<p><strong>Treatment depends on the severity of the symptoms of rhinitis. Medication usually involves interfering in order to relieve congestion in the nose. An allergic patient should know that the best means of treatment is avoiding or eliminating exposure to the allergen. Other types of medication used do not cure the allergy, they just treat the symptoms. Types of treatment used include:</strong></p><p><strong>1. Salt solutions used to rinse out the nose, they may be applied up to several times a day.</strong></p><p><strong>2. Taking anti-histamines, which lower the levels of histamines in the bloodstream. Histamines are the compounds which trigger an allergic reaction. </strong></p><p><strong>3. Cortisones are a type of medication which helps in lowering inflammation and secretion. They can be taken in the form of a nasal spray or a tablet. </strong></p><p><strong>4. Leukotriene antagonists: leukotrienes serve as one of the mediators of inflammation, and antagonists of such compounds serve as decongestants. </strong></p><p><strong>If all of the above yields no satisfactory results, then immunotherapy is employed, as well as the usage of vaccines with allergen content, in order to lower the patient's sensitivity to the allergen.</strong></p><p> </p><p> </p>
<p><strong>Continous suffering from the symptoms of allergic rhinitis may be cause for other health complications which include:</strong></p><p><strong>1. The development of nasal polyps (small tissue masses similar to a teardrop, which are caused by constant inflammation).</strong></p><p><strong>2. Large polyps may cause breating difficulties, especially while asleep, a reduced sense of smell, a blockage of the sinuses, and at times resulting in chronic sinusitis. </strong></p><p><strong>3. Middle ear infections, an infection of the eustachian tube may spread to the middle ear. Symptoms associated with this is ear pain, high fever, reduced hearing capability. </strong></p><p><strong>4. A case of allergic rhinitis which has been medicated poorly or has gone unmedicated, may lead to the development of a bronchial asthma or in cases of preexisting asthma, a worsening of the asthma symptoms. </strong></p><p> </p>
<p><strong>Preventing the condition is the best medication available for allergic rhinitis, meaning either avoiding or eliminating exposure to the allergen. This is not an easy feat to perform, and not always possible. </strong></p><p><strong>1. To prevent the formation of house dust the patient is advised to use: antiallergenic mattresses, linens and other types of covers. The house should always be cleaned with a vacuum cleaner.</strong></p><p><strong>2. When the allergy is caused by domestic animals: if you cannot remove the animal from the house, then you must make sure they do not enter your bedroom, and the house must be cleaned often. Do not allow the animals to tread upon carpets. </strong></p><p><strong>3. When the allergy is caused by pollens: avoid pollination season (usually spring/autumn), use sunglasses, and ventilate the house frequently, avoid grassy areas and parks.</strong></p><p><strong>4. When the allergy is caused by spores, maintain a dry and well-ventilated household. </strong></p><p> </p><p> </p>