What Causes Summer Allergies?

Summer Allergies

Although spring most readily comes to mind when we think of allergies, many of the same allergic triggers that can make us miserable in the spring persist into summer. Add heat, humidity, and air pollution into the mix, and you have the recipe for summer allergies.

What Causes Summer Allergies?

Just as in spring, the biggest summer allergy trigger is pollen -- tiny grains released into the air by male trees, grasses, and weeds for the purpose of fertilizing other plants. When these pollen cells get into the noses of certain people, they send the immune system into overdrive.

The immune system, mistakenly seeing the pollen as foreign invaders, releases antibodies -- substances that normally identify and go after bacteria, viruses, and other illness-causing organisms. The antibodies attack the allergens, which leads to the release of chemicals called histamines into the blood. Histamines trigger the runny nose, itchy eyes, and other summer allergy symptoms.

Pollen can travel for miles, spreading a path of misery for summer allergy sufferers along the way. The higher the pollen count, the greater the misery. The pollen count measures the amount of allergens in the air in grains per cubic meter. You can find out the daily pollen count in your area by watching your local weather forecast, or by visiting the American Academy of Allergy, Asthma and Immunology’s web site.

Trees are generally done pollinating by late spring, leaving grasses and weeds as the biggest contributors to summer allergies.

Here are some of the worst summer allergy offenders:

Weeds

Ragweed

Cockleweed

Pigweed

Russian thistle

Sagebrush

Tumbleweed

Grasses

Bermuda

Blue grasses

Orchard

Red Top

Sweet vernal

Timothy

One of the most prevalent summer allergy-inducing plants is ragweed, which typically makes its annual appearance in August. Ragweed can travel for hundreds of miles on the wind, so even if it doesn’t grow where you live, it can still make you miserable if you’re allergic to it.

If all of these airborne allergens aren’t bad enough, add summer air pollution to the mix. One of the most common pollutants is ozone, which is created in the atmosphere by a combination of sunlight, nitrogen oxide, and hydrocarbons from burning fuel. The stronger sunlight and calmer winds during the summer months can create clouds of ozone around some cities. Studies have found that ozone and other air pollutants worsen symptoms of allergies and asthma.

Another airborne allergen is of the flying, stinging variety. Bees, wasps, yellow jackets, hornets, and other insects can cause allergic reactions in some people when they sting. In up to 5% of the population, insect stings can be life threatening.

Although most summer allergens are found outdoors, culprits exist indoors as well. Molds flourish in damp areas of homes, including the basement and bathrooms. Their spores get into the air and can cause problems for allergy sufferers both in the summer, and year-round.

Dust mites -- microscopic, spider-like insects -- are another common indoor allergen. Because they thrive in warm, humid temperatures, dust mite populations peak during the summer months. They nest in beds, fabric, and carpets. Their residue can get into the air, and into your nose, triggering sneezes, wheezes, and runny noses.

What are the Symptoms of Summer Allergies?

Summer allergy symptoms caused by pollen are called allergic rhinitis (hay fever). These symptoms include:

  • Runny nose
  • Watery eyes
  • Sneezing
  • Coughing
  • Itchy eyes and nose
  • Dark circles under the eyes

Ragweed also can contribute to a condition known as oral allergy syndrome (OAS), which causes people to develop an itchy and swollen throat when they eat banana, cucumber, melon, or certain other fruits and vegetables.

Airborne allergens also can trigger asthma, a condition in which the airways narrow, making breathing difficult and leading to coughing, wheezing, and shortness of breath.

Allergic reactions to insects generally cause mild symptoms, such as itching and localized swelling. But in a small percentage of the population they can lead to a severe allergic reaction, with swelling of the throat or tongue, dizziness, nausea, and shock. This is an emergency and requires immediate medical assistance.

How are Summer Allergies Diagnosed?

If your watery, itchy eyes and runny nose aren’t going away and they’re interfering with your life, it’s probably time to see a specialist to find out what is triggering your summer allergies.

An allergy specialist will likely do a skin test, which involves injecting a tiny sample of a weakened allergen just under the skin of your arm or back. If you’re allergic to a substance, a small red bump called a hive will form. This means that your body is producing antibodies to the allergen. Another diagnostic option is the radioallergosorbent test (RAST) -- a blood test that detects antibody levels to a particular allergen.

The RAST test can also tell if you are allergic to bee stings, although it tends to have a high rate of false-positive results. A scratch test using freeze-dried bee venom is more accurate. Unfortunately, many people don’t find out that they are allergic to insect stings until they’ve had a reaction.

How are Summer Allergies Treated?

Summer allergies are treated in the same way as spring allergies, with a number of over-the-counter and prescription medications. Over-the-counter allergy drugs include:

  • Antihistamines reduce sneezing, sniffling, and itching by blocking the effects of histamine (the substance produced during an allergic reaction) in the body.
  • Decongestants clear mucus out of the nasal passageways to relieve congestion and swelling.
  • Antihistamine/decongestants combine the effects of both drugs.
  • Nasal spray decongestants relieve congestion, and may clear clogged nasal passages faster than oral decongestants.
  • Cromolyn sodium nasal spray can help prevent hay fever by stopping the release of histamine before it can trigger allergy symptoms.
  • Eye drops relieve itchy, watery eyes.
  • Nasal irrigation with warm water and salt can help clear out mucus to open sinus passages. The saline solution can be administered through a squeeze bottle or a Neti pot – a device that looks like a small teapot.

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Even though you can buy these treatments without a prescription, it’s a good idea to talk to your doctor first to make sure you choose the right one. Some antihistamines can make you feel sleepy, so you need to be careful when taking them during the day (although non-drowsy formulations are also available). Read the packaging label -- some medicines can only be used safely for a few days.

If over-the-counter remedies don’t help, your doctor may recommend one of these prescription medications:

  • Corticosteroids reduce inflammation in the nose. They are usually given in nasal spray form.
  • Leukotriene receptor antagonists (LTRAs) such as Singulair block some of the chemicals (leukotrienes) involved in allergic reactions and asthma.
  • Allergy shots expose your body to gradually increasing doses of the allergen until you become tolerant to it. They can relieve your allergy symptoms for a longer period of time than oral and nasal allergy medications. Although they don’t work for everyone, in people who do see a response, allergy shots can stave off symptoms for a few years.

Shots for people who are allergic to bee stings work in much the same way. The shots contain purified bee or other insect venom, and when you receive them over a period of a few years you gradually become tolerant to the venom. Venom allergy shots given to children may protect them for as long as 10 to 20 years.

To treat insect stings:

  • If you have an allergic reaction that causes itching all over or difficulty breathing, call 911 immediately. Inject epinephrine (adrenaline), if you have it.
  • For ordinary reactions, apply ice to the bite area to reduce swelling.
  • Use oral antihistamines (Benadryl) or topical steroids to stop the itch.

How to Deal With Summer Allergies

It’s nearly impossible to completely avoid summer allergies if your triggers are all around you. However, you can ease sniffling, sneezing, and watery eyes by avoiding your main summer allergy triggers. Here are a few tips.

  • Try to stay indoors whenever the pollen count is really high (pollen counts usually peak in the mornings).
  • Keep your doors and windows closed whenever possible during the summer months to keep allergens out. Use an air purifier, if possible.
  • Clean the air filters in your home often. Also clean bookshelves, vents, and other places where pollen can collect.
  • Wash your bedding and rugs in hot water (at least 130 degrees Fahrenheit) to eliminate dust mites and other allergens.
  • Wash your hair after going outside, because pollen can collect there.
  • Vacuum twice a week. Wear a mask because vacuuming can kick up pollen, mold, and dust that were trapped in your carpet.
  • Also wear a mask when you mow your lawn to keep grass pollen out of your nose.
  • Keep the humidity in your house between 30 and 50 percent to prevent the growth of dust mites, which thrive in humid climates.

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    To avoid insect stings:

  • Don’t wear perfume, scented lotions, or brightly colored clothing, all of which can attract bees and other stinging insects.
  • Avoid spending time in areas where there are insect nests.
  • Keep sodas, fruit, and other foods covered so that you don’t attract bees.

If you’re traveling this summer:

  • Try to choose a destination with fewer allergens, such as the beach.
  • Pack all of your allergy drugs to take with you.
  • Check with your doctor about getting an allergy shot before you leave.
  • Get the name of an allergy specialist at your destination.