Hay fever

DEFINITION

Hay fever, also called allergic rhinitis, causes cold-like signs and symptoms, such as a runny nose, itchy eyes, congestion, sneezing and sinus pressure. But unlike a cold, hay fever isn’t caused by a virus. Hay fever is caused by an allergic response to outdoor or indoor allergens, such as pollen, dust mites or pet dander.

Hay fever can make you miserable and affect your performance at work or school and interfere with leisure activities. But you don’t have to put up with annoying symptoms. Learning how to avoid triggers and finding the right treatment can make a big difference.

CAUSES

During a process called sensitization, your immune system mistakenly identifies a harmless airborne substance as something harmful. Your immune system then starts producing antibodies to this harmless substance. The next time you come in contact with the substance, these antibodies recognize it and signal your immune system to release chemicals, such as histamine, into your bloodstream. These immune system chemicals cause a reaction that leads to the irritating signs and symptoms of hay fever.

Seasonal hay fever triggers include:

• Tree pollen, common in the spring
• Grass pollen, common in the late spring and summer
• Ragweed pollen, common in the fall
• Spores from fungi and molds, which can be worse during warm-weather months

Year-round hay fever triggers include:

• Dust mites or cockroaches
• Dander (dried skin flakes and saliva) from pets, such as cats, dogs or birds
• Spores from indoor and outdoor fungi and molds

Hay fever doesn’t mean you’re allergic to hay. Despite its name, hay fever is almost never triggered by hay, and it doesn’t cause a fever.

SYMPTOMS

Hay fever signs and symptoms usually start immediately after you’re exposed to a specific allergy-causing substance (allergen) and can include:

• Runny nose and nasal congestion
• Watery or itchy eyes
• Sneezing
• Cough
• Itchy nose, roof of mouth or throat
• Sinus pressure and facial pain
• Swollen, blue-colored skin under the eyes (allergic shiners)
• Decreased sense of smell or taste

Time of year can be a factor

Your hay fever symptoms may start or worsen at a particular time of year, triggered by tree pollen, grasses or weeds, which all bloom at different times. If you’re sensitive to indoor allergens, such as dust mites, cockroaches, mold or pet dander, you may have year-round symptoms. Many people have allergy symptoms all year long, but their symptoms get worse during certain times of the year.

The effects of age

Although hay fever can begin at any age, you’re most likely to develop it during childhood or early adulthood. It’s common for the severity of hay fever reactions to change over the years. For most people, hay fever symptoms tend to diminish slowly, often over decades.

When to see a doctor

See your doctor if:

• You think you may have hay fever
• Your symptoms are ongoing and bothersome
• Allergy medications aren’t working for you
• Allergy medications work, but side effects are a problem
• You have another condition that can worsen hay fever symptoms, such as nasal polyps, asthma or frequent sinus infections

Many people — especially children — get used to hay fever symptoms. But getting the right treatment can reduce irritating symptoms. In some cases, treatment may help prevent more-serious allergic conditions, such as asthma or eczema.

You may want to see an allergy specialist (allergist) if:

• Your symptoms are severe
• Hay fever is a year-round nuisance
• Allergy medications aren’t controlling your symptoms
• Your allergy medications are causing troublesome side effects
• You want to find out whether allergy shots (immunotherapy) might be an option for you