Thursday, February 4, 2010

Airborne allergens

Airborne allergens can cause something known as allergic rhinitis, which occurs in about 15% to 20% of Americans. It develops by 10 years of age and reaches its peak in the early twenties, with symptoms often disappearing between the ages of 40 and 60.
Symptoms can include:
sneezing
itchy nose and/or throat
nasal congestion
coughing
These symptoms are often accompanied by itchy, watery, and/or red eyes, which is called allergic conjunctivitis. (When dark circles are present around the eyes, they're called allergic "shiners.") Those who react to airborne allergens usually have allergic rhinitis and/or allergic conjunctivitis. If a person has wheezing and shortness of breath, the allergy may have progressed to become asthma.
Food Allergy Symptoms
The severity of food allergy symptoms and when they develop depends on:
how much of the food is eaten
the person's sensitivity to the food
Symptoms of food allergies can include:
itchy mouth and throat when food is swallowed (some kids have only this symptom — called "oral allergy syndrome")
hives (raised, red, itchy bumps)
eczematous rash
runny, itchy nose
abdominal cramps accompanied by nausea and vomiting or diarrhea (as the body attempts to flush out the food allergen)
difficulty breathing
shock
Insect Venom Allergy Symptoms
Being stung by an insect that a child is allergic to may cause some of these symptoms:
throat swelling
hives over the entire body
difficulty breathing
nausea
diarrhea
shock
About Anaphylaxis
In rare instances, if the sensitivity to an allergen is extreme, a child may experience anaphylaxis (or anaphylactic shock) — a sudden, severe allergic reaction involving various systems in the body (such as the skin, respiratory tract, gastrointestinal tract, and cardiovascular system).
Severe symptoms or reactions to any allergen, from certain foods to insect bites, require immediate medical attention and can include:
difficulty breathing
swelling (particularly of the face, throat, lips, and tongue in cases of food allergies)
rapid drop in blood pressure
dizziness
unconsciousness
hives
tightness of the throat
hoarse voice
lightheadedness
Anaphylaxis can happen just seconds after being exposed to a triggering substance or can be delayed for up to 2 hours if the reaction is from a food. It can involve various areas of the body.
Fortunately, though, severe or life-threatening allergies occur in only a small group of kids. In fact, the annual incidence of anaphylactic reactions is small — about 30 per 100,000 people — although those with asthma, eczema, or hay fever are at greater risk of experiencing them. Most anaphylactic reactions — up to 80% — are caused by peanuts or tree nuts.
Diagnosing Allergies
Some allergies are fairly easy to identify because the pattern of symptoms following exposure to certain allergens can be hard to miss. But other allergies are less obvious because they can masquerade as other conditions.
If your child has cold-like symptoms lasting longer than a week or two or develops a "cold" at the same time every year, consult your doctor, who will likely ask questions about the symptoms and when they appear. Based on the answers to these questions and a physical exam, the doctor may be able to make a diagnosis and prescribe medications or may refer you to an allergist for allergy skin tests and more extensive therapy.
To determine the cause of an allergy, allergists usually perform skin tests for the most common environmental and food allergens. These tests can be done in infants, but they're more reliable in kids over 2 years old.
A skin test can work in one of two ways:
A drop of a purified liquid form of the allergen is dropped onto the skin and the area is pricked with a small pricking device.
A small amount of allergen is injected just under the skin. This test stings a little but isn't extremely painful. After about 15 minutes, if a lump surrounded by a reddish area appears (like a mosquito bite) at the injection site, the test is positive.
If reactions to a food or other allergen are severe, a blood test may be used to diagnose the allergy so as to avoid exposure to the offending allergen. Skin tests are less expensive and more sensitive than blood tests for allergies. But blood tests may be required in children with skin conditions or those who are extremely sensitive to a particular allergen.
Even if a skin test and/or a blood test shows an allergy, a child must also have symptoms to be definitively diagnosed with an allergy. For example, a toddler who has a positive test for dust mites and sneezes frequently while playing on the floor would be considered allergic to dust mites.
Treating Allergies
There is no real cure for allergies, but it is possible to relieve symptoms. The only real way to cope with them is to reduce or eliminate exposure to allergens. That means that parents must educate their kids early and often, not only about the allergy itself, but also about what reaction they will have if they consume or come into contact with the allergen.
Informing any and all caregivers (childcare personnel, teachers, extended family members, parents of your child's friends, etc.) about your child's allergy is equally important.
If reducing exposure isn't possible or is ineffective, medications may be prescribed, including antihistamines (which you can also buy over the counter) and inhaled or nasal spray steroids.
In some cases, an allergist may recommend immunotherapy (allergy shots) to help desensitize your child. However, allergy shots are only helpful for allergens such as dust, mold, pollens, animals, and insect stings. They're not used for food allergies, and someone with food allergies must avoid that food.
Here are some things that can help kids avoid airborne allergens:
Keep family pets out of certain rooms, like your child's bedroom, and bathe them if necessary.
Remove carpets or rugs from your child's room (hard floor surfaces don't collect dust as much as carpets do).
Don't hang heavy drapes and get rid of other items that allow dust to accumulate.
Clean frequently.
Use special covers to seal pillows and mattresses if your child is allergic to dust mites.
For kids allergic to pollen, keep the windows closed when the pollen season is at its peak, change their clothing after they've been outdoors, and don't let them mow the lawn.
Keep kids who are allergic to mold away from damp areas, such as basements, and keep bathrooms and other mold-prone areas clean and dry.
Injectable Epinephrine
Food allergies usually aren't lifelong (although those to peanuts, tree nuts, and seafood can be). Avoiding the food is the only way to avoid symptoms while the sensitivity persists.
Doctors often recommend that caregivers of kids who are extremely sensitive to a particular food, have asthma in addition to the food allergy, or are allergic to insect venom carry injectable epinephrine (adrenaline) to counteract any allergic reactions.
Available in an easy-to-carry container that looks like a pen, injectable epinephrine is carried by millions of parents (and older kids) everywhere they go. With one injection into the thigh, the device administers epinephrine to ease the allergic reaction.
An injectable epinephrine prescription usually includes two auto-injectors and a "trainer" that contains no needle or epinephrine, but allows you and your child (if he or she is old enough) to practice using the device. It's vital that you familiarize yourself with the procedure by practicing with the trainer. Your doctor also can provide instructions on how to use and store injectable epinephrine.
Make sure kids 12 years or older keep injectable epinephrine readily available at all times. If your child is younger than 12, talk to the school nurse, teachers, and your childcare provider about keeping injectable epinephrine on hand in case of an emergency.
It's also important to ensure that injectable epinephrine devices are available in your home and in the homes of friends and family members if your child spends time there. Your doctor may also encourage your child to wear a medical alert bracelet. It's also wise to carry an over-the-counter antihistamine, which can help alleviate allergy symptoms in some people. But antihistamines should not be used as a replacement for the epinephrine pen.
Kids who have had to take injectable epinephrine should go immediately to a medical facility or hospital emergency department, where additional treatment can be given if needed. Up to one third of anaphylactic reactions can have a second wave of symptoms several hours following the initial attack, so these kids might need to be observed in a clinic or hospital for 4 to 8 hours following the reaction even though they seem well.
The good news is that only a very small group of kids will experience severe or life-threatening allergies. With proper diagnosis, preventive measures, and treatment, most kids can keep their allergies in check and live happy, healthy lives.
Reviewed by: William J. Geimeier, MDDate reviewed: July 2009
diarrhea
shock
About Anaphylaxis
In rare instances, if the sensitivity to an allergen is extreme, a child may experience anaphylaxis (or anaphylactic shock) — a sudden, severe allergic reaction involving various systems in the body (such as the skin, respiratory tract, gastrointestinal tract, and cardiovascular system).
Severe symptoms or reactions to any allergen, from certain foods to insect bites, require immediate medical attention and can include:
difficulty breathing
swelling (particularly of the face, throat, lips, and tongue in cases of food allergies)
rapid drop in blood pressure
dizziness
unconsciousness
hives
tightness of the throat
hoarse voice
lightheadedness
Anaphylaxis can happen just seconds after being exposed to a triggering substance or can be delayed for up to 2 hours if the reaction is from a food. It can involve various areas of the body.
Fortunately, though, severe or life-threatening allergies occur in only a small group of kids. In fact, the annual incidence of anaphylactic reactions is small — about 30 per 100,000 people — although those with asthma, eczema, or hay fever are at greater risk of experiencing them. Most anaphylactic reactions — up to 80% — are caused by peanuts or tree nuts.

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