Allergic Rhinitis-Types, Clinical Features, Prevention, and Treatment

Allergic rhinitis is an inflammation in the nose, caused due to the body’s overreaction to the allergens present in the environment.

It is a very common type of allergy that affects a vast population. Approximately 10-30 % of adults and 40 % of children are affected by it. It is most common between the ages of twenty and forty. People with allergic rhinitis may also have asthma, atopic dermatitis, or allergic conjunctivitis.

Allergic rhinitis is characterized by sneezing, nasal congestion, nasal itching, watery nose and eyes, etc.

The disease itself is not life-threatening (unless accompanied by severe asthma or anaphylaxis). However, it does result in significant morbidity and can impair the quality of life resulting in loss of productivity.

Types of Allergic Rhinitis

Allergic rhinitis is of two types:

Seasonal (hay fever): It occurs due to the presence of outdoor allergens like pollen and/or mold spores present in the air. These particles are carried through the air and can be easily inhaled. Symptoms occur only during a particular season like spring, late summer, and autumn. The word ‘hay fever’ is a misnomer since neither it is caused due to hay nor is it associated with fever.
Perennial: It occurs due to allergens that may be present throughout the year such as dust mites, pet hair or dander, or mold. Most of these allergens are present indoors. Symptoms can occur all through the year.

Triggers and Risk factors

Outdoor allergens: pollens, weeds, and mold spores
Indoor allergens: pet hair or dander, dust mites, and mold
Irritants: cigarette smoke, perfume, hair spray and fumes, air fresheners, cleaning solutions

Clinical Features

Common symptoms of allergic rhinitis include:

Sneezing
Runny nose
Watery eyes
Itchy eyes, nose, ears and mouth
Sore or scratchy throat
Stuffy nose
Reduced sense of smell
Cough
Feeling of clogged ears
Dark circles under the eyes
Puffiness under the eyes
Headache
Fatigue and irritability
Eczema-like symptoms on skin including excessively dry and itchy skin along with blisters and oozing sores
Skin hives

Complications of Allergic Rhinitis

Inability to sleep at night due to symptoms
Frequent ear infections (otitis media)
Development or worsening of asthma symptoms
Acute or chronic sinusitis
Frequent headaches
Dental problems due to excessive breathing through the mouth because of blocked nose
Eustachian tube dysfunction
Palatal abnormalities

Diagnosis of Allergic Rhinitis

A complete physical examination should be carried out by the treating physician. A detailed history including family history, the appearance of symptoms in presence of particular substances, season, time of the day, etc. is noted.

Skin testing

It is the most common method of allergy testing. It identifies the actual substance to which a person is allergic. Minute quantities of different substances (allergens) are injected into the skin to determine the body’s reaction to each substance. In case a person is allergic to a particular substance, a small red bump will appear at the site of injection.

RAST (Radioallergosorbent test) or FEIA (Fluorescence enzyme immunoassay)

These tests can be used to measure the amount of immunoglobulin E antibodies present in the body against particular allergens.

Total serum IgE levels

It is not sensitive or specific for allergic rhinitis. However, raised levels indicate an underlying allergy.

Complete blood count (or CBC test)

A raised eosinophilic count may be seen in allergies. Similar to total IgE levels, it is neither sensitive nor specific for allergic rhinitis.

Prevention

Avoiding the allergen

Outdoor exposure

During high pollen periods, stay indoors as much as possible.
Keep windows and doors closed.
Avoid using window fans that may draw pollens or molds into the house. Use air conditioning instead.
Don’t hang clothes, towels, or beddings outdoors to dry as pollen may cling to them.
When outdoors, cover your eyes with glasses or sunglasses and also your nose and mouth to minimize the amount of pollen entering your body.

Indoor exposure

Keep your air conditioning unit clean.
Reduce exposure to dust mites. Use “mite-proof” bedding covers. Wash your bedding frequently, using hot water.
Replace carpeting with hardwood, tile, or linoleum, all of which are easier to keep dander-free.
To control mold, keep the humidity in your home low. Areas that are prone to dampness and high humidity like bathrooms, kitchen, and basement should be cleaned regularly. A dehumidifier can also be used to control humidity.
If mold is visible, it can be cleaned with a mild detergent and a 5% bleach solution.
Always clean the floors, doors, and windows with a damp mop, rather than dry sweeping or dusting.
After coming in contact with your pet, wash your hands thoroughly.
In case you are allergic to your pet, keep it out of your home as much as possible. If it has to be kept inside, do not allow it inside your bedroom.

Treatment

Intranasal corticosteroids

They are the most effective drug for treating allergic rhinitis. They help to reduce sneezing, nasal congestion as well as, itching.

As compared to oral or injectable steroids, intranasal corticosteroid sprays have lesser side-effects.

The most common side effects are local irritation and nasal bleeding.

Antihistaminics

Antihistaminics or H-1 receptor blockers are anti-allergic drugs used to treat allergic rhinitis. They act by blocking the effect of histamine. Histamine is the chemical released within the body during an allergic reaction and is responsible for causing symptoms of allergy.

They are available in the form of oral tablets, syrup, nasal sprays, and eyedrops. Commonly used drugs are hydroxyzine, diphenhydramine, chlorpheniramine, cetirizine, loratadine, and fexofenadine. Some of them are also available as over-the-counter drugs meaning they do not require a prescription.

Side effects and precautions:

Sedation and drowsiness. Older (first-generation) antihistamines cause significant sedation that may lead to accidents or injuries. So it is important not to drive a vehicle or work with dangerous machinery while taking these medicines. Even if taken at bedtime, these drugs may cause significant cognitive impairment (related to alertness learning, and memory) the next day.

Alcohol and tranquilizers increase the sedative effect of antihistamines. The newer (second-generation) antihistaminics produce lesser sedation. Non-sedative alternatives like fexofenadine may be used if sedation is not acceptable to the patient.

Decongestants

They help to relieve the stuffiness of the nose and reduce sinus pressure.

They are available in the form of oral preparations as well as nasal sprays.

Oral decongestants are often found in combination with antihistamines or other medications. Nasal sprays are very effective as they work within minutes and the effect lasts for many hours.

Commonly used decongestants include oxymetazoline, pseudoephedrine, phenylephrine, cetirizine with pseudoephedrine.

They should be used for a short period; over a maximum duration of 3-7 days. Using them for a prolonged duration can cause atrophy of the nasal lining and a rebound effect which means that the symptoms can get actually worse once you stop the treatment.

Patients suffering from heart disease, arrhythmias, high blood pressure, or a history of stroke must consult their doctor before starting these medications. Patients with anxiety, sleep disorder, or men suffering from prostate enlargement should also exercise caution while using decongestant drugs.

Other nasal sprays

Saline nasal sprays are useful for treating symptoms like dry nasal passages or thick nasal secretions. In contrast to decongestant nasal sprays, saline nasal sprays can be used as often as needed. Washing (douching) of the nasal passage may also be done using saline solution. Neti pots or saline rinse bottles may be used for performing saline rinses.
Cromolyn nasal sprays block the release of allergy-causing substances by the nose. It is useful if taken prior to exposure to an allergen. They may take several weeks to produce a significant improvement.
Ipratropium bromide nasal spray can help to reduce nasal drainage in case of allergic rhinitis.
Antihistamine nasal spray help to relieve nasal congestion and postnasal drainage. They may be used alone or in combination with other medications such as oral antihistamines or intranasal steroids. Commonly used drugs are azelastine and olopatadine. They produce quick action and can be used as and when required. Similar to oral antihistamines, they may cause sedation in some patients. In addition, azelastine has an unpleasant taste.

Leukotriene pathway inhibitors

Drugs like montelukast, zafirlukast, and zileuton block the action of leukotriene, a substance produced by the body which is responsible for causing allergic symptoms as in asthma and allergic rhinitis.

Immunotherapy

It is given to people who don’t respond well to the above-mentioned medications or those who experience severe side effects from those medications. It can also be given to people who are constantly exposed to allergens and can’t avoid it.

Immunotherapy can effectively control symptoms of allergic rhinitis. However, it does not have a role in nonallergic rhinitis.

It is of two types

Allergy shots: It involves giving gradually increasing doses of the substance to which the person is allergic (allergen). A diluted extract of allergen is given by injection over a period of few years. The increasing amount of allergen given over a period of time causes the immune system to become less sensitive to it. Thus in case of any contact with the allergen in the future, the allergic symptoms produced will be of much lesser intensity.
Sublingual immunotherapy (SLIT): In this, a tablet is placed under the tongue which then gets absorbed. The treatment should be started several months before the beginning of allergy season. At present, this therapy is used for only a few allergens like certain grass, ragweed pollens and house dust mite. It however appears to be quite promising for the future.

Eyedrops

Eyedrops containing anti-allergy medications may be used in case the allergens cause allergic symptoms in the eyes such as redness, swelling, watery eyes, and itching.

Long-Term Outlook

There is no definite cure for allergic rhinitis.

Seasonal allergic rhinitis is mostly not severe and can be controlled or minimized by avoiding the allergen and taking appropriate medicines.

Severe forms of the disease usually require long-term treatment.

References

Bhattacharyya N. Incremental healthcare utilization and expenditures for allergic rhinitis in the United States. Laryngoscope. 2011 Sep. 121(9):1830-3.
Togias AG. Systemic immunologic and inflammatory aspects of allergic rhinitis. J Allergy Clin Immunol. 2000 Nov. 106(5 Suppl): S247-50.
Thompson AK, Juniper E, Meltzer EO. Quality of life in patients with allergic rhinitis. Ann Allergy Asthma Immunol. 2000 Nov. 85(5):338-47; quiz 347-8.
Blaiss MS. Quality of life in allergic rhinitis. Ann Allergy Asthma Immunol. 1999 Nov. 83(5):449-54.
Druce HM. Allergic and nonallergic rhinitis. Middleton EM Jr, Reed CE, Ellis EF, Adkinson NF Jr, Yunginger JW, Busse WW, eds. Allergy: Principles and Practice. 5th ed. St. Louis, Mo: Mosby Year-Book; 1998. 1005-16.

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