Allergic Rhinitis

How allergic rhinitis works

When someone with a tendency to allergies (atopy) first encounters an allergen, the immune system mistakenly makes IgE antibodies against it. These attach to mast cells in the lining of the nose and eyes. On later exposure, the allergen binds the IgE, and mast cells release histamine and other chemicals within minutes. This causes sneezing, itching and a watery discharge. Hours later, a second wave of inflammation causes nasal blockage, which can persist as long as exposure continues.

Allergic rhinitis often runs in families and is linked with asthma, eczema and food allergies. About 3 in 4 people with asthma also have allergic rhinitis, and poorly controlled rhinitis can worsen asthma.

Types

Seasonal allergic rhinitis

Known as hay fever, it is triggered by pollen and occurs at predictable times of year:

• Tree pollen: late winter to spring
• Grass pollen: late spring and summer
• Weed pollen, such as ragweed: late summer and fall
• Outdoor mold spores: summer and fall, especially in damp weather

Perennial allergic rhinitis

Symptoms occur year-round, often worse indoors or in the morning. Triggers include:

• dust mites, in bedding, carpets and upholstery
• pet dander, especially cats and dogs
• indoor mold
• cockroach and rodent allergens

Perennial rhinitis tends to cause more blockage and less sneezing than seasonal.

Occupational allergic rhinitis

Triggered by allergens at work, such as flour (bakers), lab animals, latex and wood dust. It can lead to occupational asthma.

Symptoms

• sneezing, often in bouts
• runny nose with clear, watery mucus
• blocked or stuffy nose
• itchy nose, roof of the mouth, throat and ears
• itchy, red, watery eyes (allergic conjunctivitis)
• post-nasal drip and cough
• reduced sense of smell
• tiredness and poor sleep from blockage
• headache and facial pressure

Signs often seen in children include dark circles under the eyes ("allergic shiners"), rubbing the nose upward (the "allergic salute") and a crease across the nose, and mouth breathing.

Allergic rhinitis vs a cold

Non-allergic rhinitis

Some people have similar nose symptoms without an allergy. Triggers include cold air, strong smells, smoke, spicy food, pregnancy and certain medicines. Overuse of decongestant nasal sprays causes rhinitis medicamentosa, a rebound congestion. Allergy tests are negative in non-allergic rhinitis.

Diagnosis

Diagnosis is usually based on symptoms, their pattern and an examination of the nose. Allergy testing confirms the trigger and is useful when symptoms are not controlled, the cause is unclear, or immunotherapy is being considered:

• Skin-prick test: tiny amounts of allergens are pricked into the skin of the forearm. A raised itchy bump within 15 to 20 minutes shows sensitization. Antihistamines must be stopped for several days beforehand.
• Blood test (specific IgE): measures antibodies to particular allergens. Useful if skin testing is not possible.

A positive test only matters if it matches your symptoms and exposures. An ear, nose and throat specialist may use a small camera (nasal endoscopy) to check for polyps or other causes of blockage.

Treatment

Avoiding triggers

• Pollen: keep windows closed in high-pollen seasons, check daily pollen forecasts, shower and change clothes after being outdoors, and dry laundry indoors.
• Dust mites: use allergen-proof covers on mattresses and pillows, wash bedding weekly in hot water (at least 54 °C or 130 °F), reduce carpets and clutter, and keep humidity below 50 percent.
• Pets: keep pets out of the bedroom, and use a HEPA air filter.
• Mold: fix leaks and damp areas, and ventilate bathrooms and kitchens.

Medicines

• Steroid nasal sprays (fluticasone, mometasone, budesonide, triamcinolone): the most effective single treatment, especially for blockage. They take several days to reach full effect. Use daily throughout the season, aiming the nozzle slightly outward, away from the septum.
• Non-drowsy oral antihistamines (cetirizine, loratadine, fexofenadine): good for sneezing, itching and runny nose. Older antihistamines such as diphenhydramine cause drowsiness and are best avoided.
• Antihistamine nasal sprays (azelastine, olopatadine): work within minutes. Combination sprays with a steroid help moderate to severe symptoms.
• Saline nasal rinses: wash out allergens and mucus. Use distilled, sterile or previously boiled water.
• Antihistamine eye drops for itchy eyes.
• Decongestants: short-term only. Nasal decongestant sprays should not be used for more than 3 days. Oral decongestants are not suitable for people with high blood pressure, heart disease or glaucoma.
• Leukotriene receptor antagonists (montelukast): sometimes used, especially with asthma, but carry a warning about mood and behavior changes.

Follow the label dose for all over-the-counter medicines, and check with a pharmacist before giving them to children.

Allergen immunotherapy

For people whose symptoms are not controlled with medicines or who want long-term relief, immunotherapy retrains the immune system:

• Allergy shots (subcutaneous immunotherapy): regular injections of increasing doses of allergen, given for 3 to 5 years.
• Under-the-tongue tablets (sublingual immunotherapy): available for grass, ragweed and dust mite allergy, taken daily at home after a first supervised dose.

Immunotherapy can reduce symptoms for years after stopping and may lower the risk of developing asthma in children.

Complications

• poor sleep, daytime tiredness and reduced concentration at school or work
• worsening asthma
• sinusitis and ear infections, especially in children
• nasal polyps in some people

Frequently asked questions

What is the difference between allergic rhinitis and hay fever?

Hay fever is the seasonal form of allergic rhinitis, triggered by pollen. Allergic rhinitis also includes perennial (year-round) allergies to dust mites, pets, mold and cockroaches. The symptoms and treatments are largely the same.

What is the best treatment for allergic rhinitis?

A daily steroid nasal spray is the most effective single treatment, especially for a blocked nose. Non-drowsy antihistamines help sneezing and itching. Combining these with avoiding triggers and saline rinses controls symptoms for most people. Immunotherapy helps those with persistent symptoms.

Can allergic rhinitis go away?

It can improve over time, and some children outgrow it, but in many people it persists for years. Allergen immunotherapy is the only treatment that changes the underlying allergy and can give lasting relief after a 3 to 5 year course.

Is allergic rhinitis contagious?

No. Allergic rhinitis is an immune reaction to allergens, not an infection, so it cannot spread from person to person. If you have fever, body aches or colored mucus with symptoms that started after contact with someone sick, a cold is more likely.

Can allergic rhinitis cause asthma?

Allergic rhinitis and asthma often occur together and share the same allergic process. Uncontrolled nasal allergies can make asthma worse. Treating allergic rhinitis well, and immunotherapy in children, may reduce asthma symptoms and risk.