The main symptoms of allergic rhinitis are rhinorrhea (increase in nasal secretion), pruritus, sneezing fits, obstruction and congestion of the nasal pathway . Other characteristic physical findings include conjuctival swelling and erythema, eyelid swelling, lower eyelid venous stasis and effusion from the middle ear.
Allergy testing often shows what allergens an individual is sensitive to. The most common form of allergy testing is skin testing . This often involves a patch test to see what particular substances are causing the condition. In less common situations, the suspected allergen is dissolved and dropped onto the lower eyelid as a means of testing for allergies. The lower eyelid test may be harmful when done improperly. When it is established that an individual cannot undergo skin testing, the RAST blood test is helpful in determining specific allergen sensitivity. In a differential leukocyte count, peripheral eosinophilia is seen.
The main goal of treatment is to prevent or reduce the symptoms that are brought about with the inflammation of the affected tissues . Measures that have been proven effective include avoiding the allergen. When medications are required, intranasal corticosteroids are the preferred treatment. Other options can be used when these turn out to be ineffective. Antihistamines and steroids are also effective.
Allergic rhinitis is triggered by the pollens of specific seasonal plants. It is known as hay fever because its prevalence is highest during the haying season. The condition however, can affect people round the year . The causative pollen agent varies amongst individuals and also from region to region but in general, the pollens of wind-pollinated plants are the main cause. Pollens of insect pollinated plants cannot cause allergic rhinitis because they are not able to remain airborne for long and do not carry any risks . Below are some plants that have been implicated as etiologic factors for allergic rhinitis.
The Balsam of Peru, which is seen in fragrances and other products, may also cause allergic rhinitis.
In the United States, allergic rhinitis affects an estimated 40 million people. Recent figures also suggest a cumulative prevalence rate of 20% .
Internationally, the prevalence may vary within and among different countries. In Scandinavia, studies points to a 15% prevalence rate in men and 14% prevalence rate in women. This may be due to geographic differences in the types as well as potency of the overall aeroallergen burden.
Allergic rhinitis is basically an inflammation of the mucous membranes of the nose, eyes, sinuses, pharynx, middle ear and Eustachian tubes . Inflammation of the mucous membranes is characterized by a complex interaction of inflammatory mediators but it is chiefly triggered by a response to an extrinsic protein triggered by an immunoglobulin E (IgE).
The ability to develop allergic or IgE mediated reactions following exposure to extrinsic allergens has a genetic composition. In individuals who are susceptible, exposure to any of the foreign proteins brings about allergic sensitisation. This is characterized by the production of specific IgE directed against these proteins.
This specific IgE coats the surface of the mast cell seen in the nasal mucosa. Following inhalation of a specific pollen grain, it binds to IgE on the mast cells and this leads to the immediate or delayed release some mediators such as histamine, tryptase, chymase, kinins, and heparin. These mediators following various interactions bring about the symptoms consistent with allergic rhinitis.
There is no clear prevention path to avoid getting hay fever. A few suggestions point to the avoidance of exposure to allergy inducing substances such as dust mites and animal dander but there is no clear evidence on this yet as susceptible people still develops hay fever even with careful avoidance.
For people with hay fever, the best thing to do is to take steps to lessen the exposure to the allergens that cause the symptoms  and taking allergy medications before exposure to allergens as directed by medical personnel.
Hay fever is a condition more correctly known as allergic rhinitis. It is seen when an allergen like pollen, dust or particles off an animal such as hair or shed skin gets inhaled by an individual who has a susceptible immune system . In these individuals, the allergen triggers the production of the immunoglobin E (IgE) which binds to mast cells and basophils containing histamine.
Although symptoms resembling a cold or flu can be produced following hay fever, it doesn’t bring about a fever. The disease was erroneously linked with hay because it was believed at the time that symptoms were triggered by coumarin (smell of new hay).
Hay fever or allergic rhinitis is a condition that causes symptoms that bear close resemblance to cold-like signs and symptoms such as runny nose, itchy eyes, congestion and sneezing. Unlike a cold though, hay fever is not caused by a virus. It is instead caused by an allergic response to outdoor or indoor pollens like pollen and dust mites.
Hay fever is a troublesome condition as it can affect performance at work or school and also interfere with leisure activities. In most cases, avoiding triggers and taken the right medication is the best way to manage the condition.