Hay fever

What is hay fever (allergic rhinitis)?
Allergic rhinitis, sometimes referred to as ‘hay fever', is the most common type of rhinitis. Hay fever is an inflammation of the inner layer of the nose and may be seasonal, ongoing (perennial) or related to your work environment (occupational). Brief episodes of rhinitis are usually caused by respiratory tract infections with viruses (e.g. the common cold). Chronic rhinitis is usually caused by allergies, but it can also occur from overuse of certain drugs, some medical conditions, and other unidentifiable factors.

For many people, rhinitis is a lifelong condition that waxes and wanes over time. Fortunately, the symptoms of rhinitis can usually be controlled with a combination of environmental measures, medications and immunotherapy (also called allergy shots).

Who gets hay fever?
Hay fever affects approximately 20 percent of people of all ages. The risk of developing hay fever is much higher in people with asthma or eczema and in people who have a family history of asthma or rhinitis. Hay fever can begin at any age, although most people first develop symptoms in childhood or young adulthood. The symptoms are often at their worst in children and in people in their 30s and 40s. However, the severity of symptoms tends to vary throughout life; many people experience periods when they have no symptoms at all.

Signs or symptoms of hay fever
Symptoms may vary in severity from person to person but the general symptoms of hay fever could include:

• congestion of the nose
• bouts of sneezing
• watery eyes
• itchiness of eyes and nose
• hives or rashes.
• tiredness
• feeling of weakness
• poor health
• headache
• excessive mucus production.

It may also be present in patients with asthma, eczema or chronic sinusitis. Hay fever usually develops at a young age (80% of sufferers experience symptoms before 20 years of age) and research shows that allergic symptoms and asthma tend to be hereditary.

Causes of hay fever
Hay fever is caused by a nasal reaction to small airborne particles called allergens (substances that provoke an allergic reaction). In some people, these particles also cause reactions in the lungs (asthma) and eyes (allergic conjunctivitis).
The allergic reaction is characterised by activation of two types of inflammatory cells, called mast cells and basophils. These cells produce inflammatory substances, including histamine that cause fluid to build up in the nasal tissues (congestion), itching, sneezing and runny nose. Over several hours, these substances activate other inflammatory cells that can cause persistent symptoms.

Seasonal versus perennial hay fever - Hay fever can be seasonal (occurring during specific seasons) or perennial (occurring year round). The allergens that most commonly cause seasonal hay fever include pollens from trees, grasses, and weeds, as well as spores from fungi and moulds.

The allergens that most commonly cause perennial hay fever are dust mites, cockroaches, animal dander, and fungi or moulds. Perennial hay fever tends to be more difficult to treat.

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 pollen 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.

Treatment of hay fever
The goal of treatment is to reduce allergy symptoms caused by the inflammation of affected tissues. The best ‘treatment' is to try to avoid the allergens. Avoiding exposure to pollen is the best way to decrease allergic symptoms if you tend to have severe hay fever.

You may also consider some of the following preventative measures:

• Remain indoors in the morning and evening when outdoor pollen levels are highest.
• Keep house and car windows closed and use the air conditioner if possible.
• Do not dry clothes outdoors.
• Avoid unnecessary exposure to other environmental irritants such as insect sprays, tobacco smoke, air pollution, fresh tar and paint.
• Avoid mowing the grass or doing other yard work, if possible. Avoid fields and large areas of grassland.
• Regular hand and face washing removes pollen from areas where it is likely to enter your nose.
• A small amount of petroleum jelly around the eyes and nostrils will stop some pollen from entering the areas that cause a reaction.
• Avoid bicycling or walking - instead use a method of confined transportation such as a car.
• Wear sunglasses, which reduce the amount of pollen entering the eyes.
• If very severe hay fever is experienced on a frequent basis, it may help to wear face masks designed to filter out pollen if you need to be outdoors. Nasal irrigation is particularly useful for treating drainage down the back of the throat, sneezing, nasal dryness and congestion. The treatment helps by rinsing out allergens and irritants from the nose. Saline rinses also clean the nasal lining and can be used before applying sprays containing medications, to get a better effect from the medication.
• Nasal lavage (washout) carries few risks when performed correctly. Saline nasal sprays and irrigation kits can be purchased over-the-counter. Saline mixes can also be purchased or patients can make their own solution. 
• A nasal lavage with warmed saline can be performed as needed, once per day, or twice daily for increased variety of devices, including bulb syringes, Neti pots, and bottle sprayers, may be used to perform nasal lavage with at least 200 ml (about 3/4 cup) of fluid for each nostril.

If the above measures are unsuccessful, consult your doctor as to the best method of treatment to control the symptoms. These forms of treatment include:

• fast-acting strong antihistamines which relieve the symptoms after a hay fever 'attack'. They relieve itching, sneezing and runny nose, but they do not relieve nasal congestion
• short-acting antihistamines, which are generally over-the-counter (non-prescription), often relieve mild to moderate symptoms, but may cause drowsiness. Even if the person does not feel excessively drowsy, these drugs can have a sedating effect. Thus, patients should use these with caution.

Consult your doctor before giving this medication to children, as it may affect their concentration and learning ability.
 
Longer-acting antihistamines include loratadine (Claritin®, Alavert®), desloratadine (Clarinex®), cetirizine (Zyrtec®), levocetirizine (Xyzal®), and fexofenadine (Allegra®). Loratadine and cetirizine are available without a prescription. These drugs work as well as the sedating antihistamines for rhinitis, but they are less sedating and are available in long-acting formulas. However, they may be more expensive. They cause less drowsiness, can be equally effective, and usually do not interfere with learning.

Nasal glucocorticoids (steroids delivered by a nasal spray) are the first-line treatment for the symptoms of hay fever. These drugs have few side effects and dramatically relieve symptoms in most people. Studies have shown that nasal glucocorticoids are more effective than oral antihistamines for symptom relief.

Topical decongestants may also help to reduce 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 that is difficult to control. This is also called rhinitis medicamentosa because it is caused by medication.

Side effects 
The side effects of nasal steroids are mild and may include a mildly unpleasant smell or taste or drying of the nasal lining. In some people, nasal steroids cause irritation, crusting and bleeding of the nasal septum (the cartilage that divides the two sides of the nose), especially during the winter. These problems can be minimised by reducing the dose of the nasal steroid, applying a moisturising nasal gel or spray to the septum before using the spray, or switching to a water-based (rather than an alcohol-based) spray.

Studies suggest that nasal steroids are generally safe when used for many years. However, people who use these drugs for years should have periodic nasal examinations to check for rare side effects, such as nasal infection.
Steroids taken as a pill or inhaled into the lungs can have side effects, especially when taken for long periods of time. However, the doses used in nasal steroids are low and are NOT associated with these side effects. However, clinicians usually recommend using the lowest effective dose.

 
How to use a nasal spray
Nasal sprays work best when they are used properly and the medication remains in the nose rather than draining down the back of the throat. If the nose is crusted or contains mucus, it should be cleaned with a saline nasal spray before a nasal spray that contains medication.

• The head should be positioned normally or with the chin slightly tucked. The spray should be directed away from the nasal septum. The spray is dispensed and then sniffed in slightly to pull it into the higher parts of the nose. Sniffing too hard will result in the medicine draining down the throat, and should be avoided.
• Some people find that holding one nostril closed with a finger improves their ability to draw the spray into the upper nose. Medicine that drains into the throat may be spit out.

‘Allergy shots' are occasionally recommended if the allergen cannot be avoided and if symptoms are hard to control. This includes regular injections of the allergen, given in increasing doses (each dose slightly larger than the previous dose) that may help the body adjust to the antigen. They may also increase the risk of triggering a secondary allergic reaction such as an asthma attack.

Although immunotherapy can be expensive, many insurance plans cover the therapy because long-term use of allergy medications is also costly. Immunotherapy is usually started by an allergist. Treatment begins with several months of weekly injections of gradually increasing doses, followed by monthly maintenance injections. The maintenance injections can be given by a primary care provider. Immunotherapy is usually a long-term therapy, and the benefits of this therapy may lessen when it is discontinued. However, one study in people with allergies to grass pollen found that the benefits of three to four years of immunotherapy persisted when the injections were stopped.

Immunotherapy injections carry a small risk of a severe allergic reaction. These reactions occur with a frequency of six of every 10 000 injections. The symptoms usually begin within 30 minutes of the injection. For this reason, patients are required to remain in the office after routine injections so that such a reaction could be quickly treated. Because drugs called beta-blockers may interfere with the ability to treat these reactions, people who take beta-blockers are often advised to avoid immunotherapy.

Other treatments
Other drugs may be recommended for some people with hay fever:
Ipratropium: Nasal atropine is effective for the treatment of severe runny nose. This drug, available as ipratropium bromide (Atrovent®), is not generally recommended for people with glaucoma or men with an enlarged prostate.
Leukotriene modifiers: Release of substances called leukotrienes may contribute to the symptoms of hay fever. Drugs that block the actions of leukotrienes, called leukotriene modifiers, can be very useful in patients with asthma and hay fever. However, nasal steroids are more effective than leukotriene modifiers for treating hay fever; thus, leukotriene modifiers are generally reserved for patients who cannot tolerate nasal sprays (due to nose bleeds) or azelastine (see 'antihistamines' above).

What is the safest and most effective treatment for children with hay fever?
While some hay fever medication is safe for children, be sure to read the package insert before giving the medication to children and always check with your doctor if you are unsure.

Immunotherapy is considered safe for children over two years of age, although getting them to submit to treatment that involves needles, may not be easy. Still, it is important to take hay fever in children seriously, since it may lead to the development of asthma.

Pregnancy and hay fever
Women who have hay fever before pregnancy may experience worsening, improvement or no change in their symptoms during pregnancy. Most women notice some nasal congestion in the later stages of pregnancy, even if they did not have rhinitis before. This is called rhinitis of pregnancy, and is related to hormone levels. Rhinitis of pregnancy does not respond to medication and goes away after delivery. The discussion below applies only to hay fever.

As a general rule, medication that controls symptoms should be avoided or used at the lowest dosage during pregnancy. A pregnant woman should always review any medication (over-the-counter or prescription) before taking it. However, several of the drugs used to treat hay fever are considered safe. Women with mild rhinitis may be able to control symptoms using only saline nasal sprays or irrigation, which do not contain any medications. 

If medication for rhinitis is needed during pregnancy, the following are considered to be safer choices:

• Nasal sprays - certain nasal sprays are a sensible option for pregnant women, because much less drug is required to control symptoms when it is sprayed directly into the nose, compared to taking that same medication by mouth.
• Cromolyn nasal sprays are safe for use during pregnancy. Only a very small amount of drug is absorbed into the bloodstream with this medication and no serious side effects are known to occur.
• Nasal glucocorticoids are considered safe for use in pregnancy, and women who are already taking these can simply continue during pregnancy. Although no safety differences have been identified among the different nasal glucocorticoids, budesonide (Rhinocort Aqua®) has been approved for use during pregnancy for a longer time than the others.
• Antihistamines - Chlorpheniramine (Chlor-Trimeton® and others), loratadine (Claritin®), or cetirizine (Zyrtec®) are the antihistamines of choice during pregnancy.
• Decongestants - Pseudoephedrine should be avoided during the first trimester of pregnancy if possible, because its safety has not been confirmed. After the first trimester, it should be used only when needed and only as directed. However, it should not be used at all by women with high blood pressure or pre-eclampsia. Phenylephrine should be avoided altogether during pregnancy.
• Allergy shots - Women already taking allergy shots who have not had allergic reactions to the shots in the past may safely continue treatment through pregnancy. However, the dose should not be increased during pregnancy due to the risk of a serious allergic reaction (anaphylaxis), which could potentially reduce the blood supply to the foetus. For the same reason, allergy shots are not started during pregnancy.

What is allergy testing?
There are many methods of allergy testing. Among the more common are:

• Skin tests: This test involves placing a small amount of suspected allergy-causing substances on the skin, usually the forearm, upper arm, or the back. Then, the skin is pricked so the allergen goes under the skin's surface. The healthcare provider closely watches the skin for signs of a reaction (usually swelling and redness of the site). Results are usually seen within 15 to 20 minutes. Several allergens can be tested at the same time.
• Elimination tests: An elimination diet can be used to check for food allergies. An elimination diet is one in which foods that may be causing symptoms are removed from the diet for several weeks and then slowly re-introduced one at a time while the person is watched for signs of an allergic reaction.
• Blood tests: Blood tests can be done to measure the amount of immunoglobulin (Ig) E antibodies to a specific allergen in the blood. This test may be used when skin testing is not helpful or cannot be done.