Allergy: Hay fever overview.

Introduction

If spring brings a stuffy nose, scratchy eyes and an extra sneeze tacked on to your usual "achoo!" - you probably have hay fever (allergic rhinitis). Hay fever is the common name for an allergic response to specific substances in your environment. Hay fever is one of the most common allergic conditions, affecting about 40 million people in the United States.
If you have seasonal hay fever, tree pollen, grasses or weeds may trigger your symptoms. If you're sensitive to indoor allergens such as dust mites, cockroaches, mold or pet dander, you may have year-round symptoms.
Over-the-counter medications may be enough to manage your mild hay fever symptoms. But if your signs and symptoms are more severe - or if hay fever is a year-round nuisance - see an allergy specialist for evaluation and treatment. Without proper treatment, hay fever can impair your quality of life, cause sleeplessness, fatigue and irritability that affect your performance at work or school, and increase your risk of developing more serious allergic conditions such as asthma or eczema.

Signs and symptoms

Signs and symptoms of hay fever can range from mild to severe. If your condition is mild, you may have brief, infrequent episodes of a runny nose and itchy, watery eyes. At the other extreme, you may experience persistent, severe symptoms that last more than four days a week or longer than four weeks at a time. Chronic congestion may cause facial pressure and pain, alter your sense of taste and smell, and affect your appearance. The skin beneath your eyes may swell and turn blue-ish as you develop what are sometimes called "allergic shiners."
Hay fever signs and symptoms usually develop immediately after you're exposed to specific allergy-causing substances (allergens). Common allergens include pollen, dust mites, cockroaches, mold and pet dander. Sometimes, exposure to irritants such as perfume and tobacco smoke may trigger or worsen symptoms.

Signs and symptoms of hay fever may include:

-- Runny nose
-- Watery eyes
-- Congestion
-- Frequent sneezing
-- Itchy eyes, nose, roof of mouth or throat
-- Swollen, blue-colored skin under eyes (allergic shiners)
-- Postnasal drip
-- Cough
-- Sleeplessness
-- Fatigue
-- Irritability
-- Facial pressure and pain

It may be difficult to distinguish hay fever from a cold. Here's how to tell the difference:

	Hay fever	Colds
Signs and symptoms	Runny nose with thin, watery discharge; no fever	Runny nose with watery to thick yellow discharge; low-grade fever
Onset	Immediately after exposure to allergens	One to three days after exposure to cold virus
Duration	As long as you're exposed to allergens	Five to seven days

Causes

Hay fever doesn't mean that you're necessarily allergic to hay. Despite its name, hay fever is almost never triggered by hay, and it doesn't cause a fever. It got its name in the early 1800s when British doctors noticed that some rural residents experienced sneezing, itchy eyes and coughing after exposure to cut hay or grass. At the time, doctors didn't realize that the probable culprit was an allergic reaction to pollen or mold. They called the condition a "fever" because it caused nervousness, one of the old English definitions of fever.

Heredity plays a key role in determining who gets allergies, including hay fever. You may be more likely to develop hay fever if allergies or asthma runs in your family.

Although hay fever can begin at any age, you're most likely to develop it during childhood or early adulthood. As you get older, your symptoms may worsen or improve. The severity of hay fever tends to diminish slowly, often over decades.

If you have hay fever, you may react to one or more common inhaled allergens. No matter what you're allergic to, the underlying cause of your misery is the same. During a process called sensitization, your immune system mistakenly identifies the allergen as an invader and produces an antibody against it called immunoglobulin E, or IgE.

The next time you're exposed to the allergen, your immune system launches an allergic reaction. The IgE antibodies trigger the release of an inflammatory chemical called histamine, which swells the mucous membranes in your nose, sinuses and eyes, causing a runny nose, watery eyes and sneezing.

Risk factors

The following risk factors may increase your risk of developing hay fever:

-- Family history of allergies
-- Male sex
-- Firstborn
-- Exposure to cigarette smoke in your first year of life
-- Exposure to indoor allergens, such as dust or pet dander

When to seek medical advice

If you have occasional signs and symptoms of hay fever and haven't found relief from using over-the-counter medications, see your doctor to design a treatment program. Also see your doctor if your problems are persistent or if you have side effects from over-the-counter medications. You may need an allergy specialist for an accurate and complete diagnosis.

Screening and diagnosis

Your doctor will ask detailed questions about your personal and family medical history, your signs and symptoms, and your usual way of treating them. Your doctor also performs a physical examination to look for additional clues about the causes of your signs and symptoms.

Your medical history and physical exam may provide enough information for your doctor to discuss your diagnosis and treatment. But if your doctor is uncertain that you have allergies, or suspects that you have allergies and needs more information about the possible causes, he or she may recommend that you have skin tests. During skin testing, small amounts of purified allergen extracts are pricked into the skin of your arm or upper back and observed for signs of an allergic reaction. A blood test can also identify possible allergens.

Complications

Even uncomplicated hay fever can affect your quality of life. Congestion and constant nose blowing can cause discomfort and embarrassment. The resulting sleeplessness, fatigue and irritability can also affect your performance at work or school.

But hay fever may increase your risk of developing more serious allergic conditions such as asthma - a chronic condition that occurs when the main air passages of your lungs, the bronchial tubes, become inflamed. Hay fever and asthma often occur together. If you have asthma, you may have signs and symptoms such as difficulty breathing, shortness of breath, a tight feeling in the chest, coughing and wheezing.

People with hay fever may also have eczema (also called dermatitis) - an inflammation of your skin characterized by swollen, reddened and itchy skin. In particular, atopic dermatitis often occurs with allergies and frequently runs in families in which family members have asthma, hay fever or both.

Prolonged sinus congestion due to hay fever may increase your susceptibility to sinusitis - an infection or inflammation of the membrane that lines the sinuses. Sinusitis causes pain, tenderness and swelling around your eyes, cheeks, nose or forehead and can be either acute or chronic.

In children, hay fever often is a contributing factor to middle ear infection (otitis media), which causes pain, fever and fluid buildup in the middle ear.

Treatment

After your doctor has identified what allergy triggers your symptoms, he or she will help you develop a plan to avoid these substances. In some cases, avoidance alone can effectively control your hay fever problems.

Your doctor may also prescribe an oral medication, a nasal spray or eyedrops - alone or in combination - to decrease your signs and symptoms. Treatments for hay fever include:

-- Nasal corticosteroids. Because corticosteroid nasal sprays are the most effective hay fever medications, they're often prescribed first, especially for more troublesome signs and symptoms. Examples include beclomethasone (Beconase), fluticasone propionate (Flonase), triamcinolone (Nasacort), budesonide (Rhinocort), flunisolide (Nasarel) and mometasone (Nasonex). Although these medications can be effective after a few days of treatment, you may not notice any improvement until after you've used them for a week or so. Nasal corticosteroids are generally safe for extended use.

Mild side effects may include an unpleasant smell or taste, or irritation, crusting and bleeding in your nose, which may be especially noticeable during the winter. This side effect can be minimized by applying a small amount of petroleum jelly (such as Vaseline) inside your nose before using a nasal steroid, by using a saline nasal spray to restore moisture or by switching from an alcohol-based to a water-based nasal steroid.

Unlike steroids taken by mouth or inhaled deeply through an inhaler or nebulizer, most nasal steroids don't appear to reduce bone density or affect growth in children. Still, to be on the safe side, doctors usually prescribe the lowest effective dose of nasal corticosteroids.

-- Antihistamines. These oral medications and nasal sprays help relieve itching, sneezing and runny nose, but have less effect on congestion. They work by blocking histamine, an inflammatory chemical released by your immune system during an allergic reaction. Over-the-counter oral antihistamines include diphenhydramine (Benadryl), chlorpheniramine (Chlor-Trimeton) and clemastine (Tavist). Because these older antihistamines may make you sleepy, avoid using them before driving or operating heavy machinery. Newer oral antihistamines - such as loratadine (Claritin), which is available over-the-counter - are less likely to cause sedation. Less-sedating oral antihistamines available by prescription include cetirizine (Zyrtec) and fexofenadine (Allegra). The prescription antihistamine nasal spray azelastine (Astelin) is effective for hay fever, but may cause drowsiness.

-- Decongestants. These medications, often used in combination with antihistamines, are available in over-the-counter and prescription liquids, tablets and nasal sprays. Oral decongestants include medications containing pseudoephedrine (Sudafed, Actifed, others). Nasal decongestants include phenylephrine (Neo-Synephrine) and oxymetazoline (Afrin). Because oral decongestants can elevate blood pressure, avoid them if you have high blood pressure (hypertension). Oral decongestants also can worsen the symptoms of prostate enlargement, making urination more difficult. Don't use a decongestant nasal spray for more than two or three days at a time because it can cause rebound signs of congestion when used longer.

-- Cromolyn sodium. This medication, available as an over-the-counter nasal spray (NasalCrom, others), helps relieve hay fever symptoms by preventing the release of histamine. Although cromolyn sodium isn't associated with any serious side effects, it's most effective when started before signs and symptoms develop and sometimes must be used three or four times a day. -- Leukotriene modifier. Montelukast (Singulair) is a prescription tablet taken to block the action of leukotrienes - immune system chemicals that cause allergy symptoms such as excess mucus production. It has proved effective in treating allergic asthma, and it's also effective in treating hay fever. Possible side effects include headache. Less common side effects include abdominal pain, cough, dental pain and dizziness.

-- Nasal atropine. Available in a prescription nasal spray, ipratropium bromide (Atrovent) helps relieve a severe runny nose by preventing the glands in your nose from producing excess fluid. It's not effective for treating congestion, sneezing or postnasal drip. Mild side effects include nasal dryness, nosebleeds and sore throat. Rarely, it can cause more severe side effects such as blurred vision, dizziness and difficult urination. The drug is not recommended for people with glaucoma or men with an enlarged prostate.

If you are taking any other medications or have a chronic health condition, talk to your doctor or pharmacist before starting any treatment for hay fever, to be sure you're not at risk of a drug interaction or other adverse effect.

-- Immunotherapy. If medications don't relieve your hay fever symptoms, your doctor may recommend allergy shots (immunotherapy or desensitization therapy). Over a period of three to five years, you receive regular injections containing purified allergen extracts. The goal is to desensitize you to specific allergens, reduce your signs and symptoms, and decrease your need for medications.

Immunotherapy may be especially effective if you're allergic to cat dander, dust mites or pollen produced by trees, grass and weeds. In children, immunotherapy may help prevent the development of asthma. Rarely, immunotherapy injections can cause a severe allergic reaction (anaphylaxis).

Self-care

It's not possible to completely avoid allergens, but you can reduce your signs and symptoms by minimizing your exposure to them. To reduce exposure to pollen or molds:

-- Close doors and windows during pollen season
-- Use air conditioning in your house and car
-- Stay indoors on dry, windy days
-- Use a dehumidifier to reduce indoor humidity
-- Use a high-efficiency particulate air (HEPA) filter in your bedroom
-- Avoid mowing the lawn or raking leaves, which stirs up pollen and molds

To reduce exposure to dust mites:

-- Use allergy-proof covers on mattresses, box springs and pillows
-- Wash sheets and blankets in water heated to at least 130 degrees Fahrenheit
-- Use a dehumidifier to reduce indoor humidity
-- Vacuum carpets weekly with a vacuum cleaner equipped with a small-particle or HEPA filter
-- Consider removing carpeting, especially where you sleep, if you're highly sensitive to dust mites

To reduce exposure to cockroaches:

-- Block cracks and crevices where roaches can enter
-- Fix leaky faucets and pipes
-- Wash dishes and empty garbage daily
-- Sweep food crumbs from counters and floors
-- Store food, including pet food, in sealed containers
-- Consider professional pest extermination

To reduce exposure to pet dander:

-- Remove pets from the house
-- Bathe pets weekly
-- Keep your pet out of the bedroom

Introduction If spring brings a stuffy nose, scratchy eyes and an extra sneeze tacked on to your usual "achoo!" - you probably have hay fever (allergic rhinitis). Hay fever is the common name for an allergic response to specific substances in your environment. Hay fever is one of the most common allergic conditions, affecting about 40 million people in the United States.
If you have seasonal hay fever, tree pollen, grasses or weeds may trigger your symptoms. If you're sensitive to indoor allergens such as dust mites, cockroaches, mold or pet dander, you may have year-round symptoms.
Over-the-counter medications may be enough to manage your mild hay fever symptoms. But if your signs and symptoms are more severe - or if hay fever is a year-round nuisance - see an allergy specialist for evaluation and treatment. Without proper treatment, hay fever can impair your quality of life, cause sleeplessness, fatigue and irritability that affect your performance at work or school, and increase your risk of developing more serious allergic conditions such as asthma or eczema.