Rhinitis

Rhinitis, commonly known as a runny nose, is the medical term describing irritation and inflammation of some internal areas of the nose. The primary symptom of rhinitis is nasal dripping. It is caused by chronic or acute inflammation of the mucous membrane of the nose due to viruses, bacteria or irritants. The inflammation results in the generating of excessive amounts of mucus, commonly producing the aforementioned runny nose, as well as nasal congestion and post-nasal drip. According to recent studies completed in the United States, more than 50 million Americans are current sufferers. Rhinitis has also been found to adversely affect more than just the nose, throat, and eyes. It has been associated with sleeping problems, ear conditions, and even learning problems. Rhinitis is caused by an increase in histamine. This increase is most often caused by airborne allergens. These allergens may affect an individual's nose, throat, or eyes and cause an increase in fluid production within these areas.

Types
Rhinitis is categorized into three types: infective rhinitis includes acute and chronic bacterial infections; Nonallergic (vasomotor) rhinitis includes autonomic, hormonal, drug-induced, atrophic, and gustatory rhinitis, as well as Rhinitis medicamentosa; allergic rhinitis, the most common of the three, is an allergic reaction triggered by pollen, mold, animal dander, dust and other similar inhaled allergens.

Vasomotor rhinitis
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Vasomotor rhinitis is also known as non-allergenic rhinitis, because it often has the same symptoms as allergies, but has different causes. Whereas allergenic rhinitis conditions (such as hayfever) are the result of the immune system overreacting to environmental irritants (pollen, etc), vasomotor rhinitis is believed to be caused by oversensitive or excessive blood vessels in the nasal membrane. These blood vessels (which are controlled in turn by the autonomic nervous system) contract or dilate in order to regulate mucus flow and congestion. But in the vasomotor rhinitis sufferer, oversensitive or excessive blood vessel dilation or contraction causes an overreaction to such stimuli as changes in weather, temperature, or barometric pressure, chemical irritants such as smoke, ozone, pollution, perfumes, and aerosol sprays, psychological stress and emotional shocks, certain types of medications, alcohol, and even spicy food. Thus, while a normal person's nose may run on a very cold day, a vasomotor rhinitis sufferer's nose may start running (or go completely dry) simply by walking into a slightly colder (or slightly warmer) room, or from eating food that is slightly warmer or cooler than room temperature. While a normal person may tolerate a certain degree of cigarette smoke, the vasomotor rhinitis sufferer may experience significant discomfort from the same level of smoke, etc.

The pathology of vasomotor rhinitis is in fact not very well-understood and more research is needed. Vasomotor rhinitis appears to be significantly more common in women than men, leading some researchers to believe hormones to play a role. In general, age of onset occurs after 20 years of age, in contrast to allergic rhinitis which generally appears before age 20. Individuals suffering from vasomotor rhinitis typically experience symptoms year-round, though symptoms may exacerbate in the spring and fall when rapid weather changes are more common.

Many patients can be subject to vasomotor rhinitis and allergic rhinitis simultaneously. Vasomotor rhinitis is a common condition that often goes unrecognized/underrecognized, especially in women. An estimated 17 million United States citizens have vasomotor rhinitis.

Allergic rhinitis
When an allergen such as pollen or dust is inhaled by a person with a sensitized immune system, it triggers antibody production. These antibodies mostly bind to mast cells, which contain histamine. When the mast cells are stimulated by pollen and dust, histamine (and other chemicals) are released. This causes itching, swelling, and mucus production. Symptoms vary in severity from person to person. Very sensitive individuals can experience hives or other rashes. Particulate matter in polluted air and chemicals such as chlorine and detergents, which can normally be tolerated, can greatly aggravate the condition.

Sufferers might also find that cross-reactivity occurs. For example, someone allergic to birch pollen may also find that they have an allergic reaction to the skin of apples or potatoes. A clear sign of this is the occurrence of an itchy throat after eating an apple or sneezing when peeling potatoes or apples. This occurs because of similarities in the proteins of the pollen and the food. There are many cross-reacting substances.

Some disorders may be associated with allergies: Comorbidities include eczema, asthma, depression and migraine.

Allergies are common. Heredity and environmental exposures may contribute to a predisposition to allergies. It is roughly estimated that one in three people have an active allergy at any given time and at least three in four people develop an allergic reaction at least once in their lives. The two categories of allergic rhinitis include:

seasonal - occurs particularly during pollen seasons. Seasonal allergic rhinitis does not usually develop until after 6 years of age.
perennial - occurs throughout the year. This type of allergic rhinitis is commonly seen in younger children.
Allergy testing may reveal the specific allergens a person is sensitive to. Skin testing is the most common method of allergy testing. This may include intradermal, scratch, patch, or other tests. Less commonly, the suspected allergen is dissolved and dropped onto the lower eyelid as a means of testing for allergies. (This test should only be done by a physician, never the patient, since it can be harmful if done improperly). In some individuals who cannot undergo skin testing (as determined by the doctor), the RAST blood test may be helpful in determining specific allergen sensitivity.

Hay fever
Pollen grains from a variety of common plants can cause hay fever.Allergic rhinitis triggered by the pollens of specific seasonal plants is commonly known as 'hay fever', because it is most prevalent during haying season. It is particularly prevalent from late May to the end of June (in the Northern Hemisphere). However, it is possible to suffer from hay fever throughout the year. The pollen which causes hay fever varies from person to person and from region to region; generally speaking, the tiny, hardly visible pollens of wind-pollinated plants are the predominant cause. Pollens of insect-pollinated plants are too large to remain airborne and pose no risk. Examples of plants commonly responsible for hay fever include:

Trees: such as birch (Betula), alder (Alnus), cedar (Cedrus), hazel (Corylus), hornbeam (Carpinus), horse chestnut (Aesculus), willow (Salix), poplar (Populus), plane (Platanus), linden/lime (Tilia) and olive (Olea). In northern latitudes birch is considered to be the most important allergenic tree pollen, with an estimated 15–20% of hay fever sufferers sensitive to birch pollen grains. Olive pollen is most predominant in Mediterranean regions.
Grasses (Family Poaceae): especially ryegrass (Lolium sp.) and timothy (Phleum pratense). An estimated 90% of hay fever sufferers are allergic to grass pollen.
Weeds: ragweed (Ambrosia), plantain (Plantago), nettle/parietaria (Urticaceae), mugwort (Artemisia), Fat hen (Chenopodium) and sorrel/dock (Rumex)
In addition to individual sensitivity and geographic differences in local plant populations, the amount of pollen in the air can be a factor in whether hay fever symptoms develop. Hot, dry, windy days are more likely to have increased amounts of pollen in the air than cool, damp, rainy days when most pollen is washed to the ground.

The time of year at which hay fever symptoms manifest themselves varies greatly depending on the types of pollen to which an allergic reaction is produced. The pollen count, in general, is highest from mid-spring to early summer. As most pollens are produced at fixed periods in the year, a long-term hay fever sufferer may also be able to anticipate when the symptoms are most likely to begin and end, although this may be complicated by an allergy to dust particles.

Prevention and treatment
The goal of rhinitis treatment is to reduce the symptoms caused by the inflammation of affected tissues. In cases of allergic rhinitis, the most effective way to decrease allergic symptoms is to completely avoid the allergen.Vasomotor rhinitis can be brought under a measure of control through avoidance of irritants, though many irritants, such as weather changes, are uncontrollable.

Allergic treatment
Main article: Allergy treatment
Allergic rhinitis can typically be treated much like any other allergic condition.

Eliminating exposure to allergins is the most effective preventive measure, but requires consistent effort.

Many people with pollen allergies reduce their exposure by remaining indoors during hay fever season, particularly in the morning and evening, when outdoor pollen levels are at their highest. Closing all the windows and doors prevents wind-borne pollen from entering the home or office. When traveling in a vehicle, closing all the windows reduces exposure. Air conditioners are reasonably effective filters, and special pollen filters can be fitted to both home and vehicle air conditioning systems.

Because many allergins clings to clothing, skin, and hair, regular cleaning reduces exposure and therefore symptoms. Many people bathe before sleeping, to minimize their exposure to potential allergins that could have stuck to their bodies during the day. Some people use nasal irrigation to physically remove contaminants from their noses.

Frequently cleaning floors and washing bedding can significantly reduce local irritants such as dust, as well as those tracked in by family, pets and visitors.

Several antagonistic drugs are used to block the action of allergic mediators, or to prevent activation of cells and degranulation processes. These include antihistamines, cortisone, dexamethasone, hydrocortisone, epinephrine (adrenaline), theophylline and cromolyn sodium. Anti-leukotrienes, such as Montelukast (Singulair) or Zafirlukast (Accolate), are FDA approved for treatment of allergic diseases. One antihistamine, Azelastine (Astelin), is available as a nasal spray.

More severe cases of allergic rhinitis require immunotherapy (allergy shots) or removal of tissue in the nose (e.g., nasal polyps) or sinuses.

Many allergy medications can have unpleasant side-effects, most notably drowsiness; more serious side-effects such as asthma, sinusitis, and even nasal polyps have also been reported however.

A case-control study found "symptomatic allergic rhinitis and rhinitis medication use are associated with a significantly increased risk of unexpectedly dropping a grade in summer examinations".

Nasal treatments
See also: Anti-inflammatory use of glucocorticoids
Systemic Glucocorticoids such as Triamcinolone or Prednisone are effective at reducing nasal inflammation, but their use is limited by their short duration of effect and the side effects of prolonged steroid therapy. Steroid nasal sprays are effective and safe, and may be effective without oral antihistamines. These medications include, in order of potency: beclomethasone (Beconase), budesonide (Rhinocort), flunisolide (Syntaris), mometasone (Nasonex), fluticasone (Flonase, Flixonase), triamcinolone (Nasacort AQ). They take several days to act and so need be taken continually for several weeks as their therapeutic effect builds up with time.

Topical decongestants: may also be helpful in reducing symptoms such as nasal congestion, but should not be used for long periods as stopping them after protracted use can lead to a rebound nasal congestion (Rhinitis medicamentosa).

Saltwater sprays, rinses or steam: this removes dust, secretions and allergenic molecules from the mucosa, as they are all instant water soluble. A suitable solution is 2-3 spoonful of salt dissolved in one litre of lukewarm water.

Alternative treatments
A large number of over-the-counter treatments are sold without FDA approval, including herbs like eyebright (Euphrasia officinalis), nettle (Urtica dioica), and bayberry (Myrica cerifera), which have not been shown to reduce the symptoms of nasal-pharynx congestion. In addition, feverfew (Tanacetum parthenium) and turmeric (Curcuma longa) has been shown to inhibit phospholipase A2, the enzyme which releases the inflammatory precursor arachidonic acid from the bi-layer membrane of mast cells (the main cells which respond to respiratory allergens and lead to inflammation) but this is only in test tubes and it is not established as anti-inflammatory in humans.

It has been claimed that homeopathy provides relief free of side-effects. However, this is strongly disputed by the medical profession on the grounds that there is no valid evidence to support this claim.

Therapeutic efficacy of complementary-alternative treatments for rhinitis and asthma is not supported by currently available evidence.

Nevertheless, there have been some attempts with controlled trials to show that acupuncture is more effective than antihistamine drugs in treatment of hay fever. Complementary-alternative medicines such as acupuncture are extensively offered in the treatment of allergic rhinitis by non-physicians but evidence-based recommendations are lacking. The methodology of clinical trials with complementary-alternative medicine is frequently inadequate.[citation needed] Meta-analyses provides no clear evidence for the efficacy of acupuncture in rhinitis (or asthma).[citation needed] Currently, evidence-based recommendations for acupuncture or homeopathy cannot be made in the treatment of allergic rhinitis.

Eating locally produced unfiltered honey is believed by many to be a treatment for hayfever, supposedly by introducing manageable amounts of pollen to the body. Clinical studies have not provided any evidence for this belief.