July 20, 2009

Allergies 101

The following article can be found in Understanding Your Child’s Health by Susan K Schulman MD., which will be available in July, 2009 (Hamodia Treasures, distributed by Israel Book Shop)

Allergic reactions in children can be manifested in many different ways. In their mildest form, they can cause a runny nose or a dry itchy patch on the skin. In their most severe form, they can cause catastrophic swelling of the airways and/or shock, which can be fatal. Here is an overview of childhood allergies.

Key Points

Allergic reactions are produced by IgE antibodies, an abnormal immune response.
The nose, eyes throat and bronchial tubes can react to environmental allergens.
The skin can react acutely, with hives, or chronically, with eczema.
The gastrointestinal tract can react with vomiting, abdominal pain, and bloody diarrhea.
Anaphylaxis is a severe allergic reaction that causes generalized itching, hives, and swelling of the lips, tongue and throat. It can also cause extreme difficulty breathing, and shock.
Anaphylaxis can be fatal. It must be treated as an acute emergency.
Avoidance of the allergen is usually the best way to prevent allergic reactions.
Identifying the allergenic substance often requires evaluation by a physician.

What are allergies?

Allergies arise from an abnormal immune response to an allergen, which could be a food, an environmental material, or a drug. Normal immune responses are beneficial, because they are directed against disease causing targets such as bacteria and viruses. The immune response in allergy is not beneficial to the child. Instead of providing protection, it actually causes illness and problems. The normal immune globulins that are produced in response to infection are Immune Globulins IgG (also known as gamma globulin) IgM, and IgA. Each globulin is directed against specific targets. For example, anti measles IgG protects against measles.

For some reason, some people are abnormally sensitive and they produce an unwanted iImmune globulin, called IgE, when exposed to certain allergenic substances. These unwanted globulins cause reactions. For example, anti egg white IgE causes a reaction when egg whites are eaten or touched. If only small amounts of IgE are produced, the reactions are likely to be mild. If very large amounts of IgE are produced, the reactions can be very severe, even life threatening.

What problems can allergies cause?

Here is a list of conditions that can be caused by allergies:

Hives, also known as urticaria. This is an itchy, blotchy skin reaction. The bumps are irregular in shape and are pink and white. About 25% of hives are caused by allergy. The rest are caused by viruses and other conditions
Eczema– This itchy, irritated skin rash is often caused by food allergy.
Allergic Rhinitis– Sneezing, itchy, watery runny nose, and nasal congestion, are common symptoms of allergic rhinitis. This problem is usually caused by allergens in the air, such as pollens, mold, and dust. What time of year is the worst? Outdoor allergies are seasonal. The spring allergy season ( mistakenly called Rose Fever) is caused by molds, tree and grass pollens. The late summer and fall allergy season( mistakenly called HayFever) is caused by ragweed pollen and mold. The indoor allergies to dust and dust mites, cockroach, and mold occur year round.(These are correctly called Perennial Rhinitis) .
Allergic conjunctivitis. The allergen causes red, itchy, watery eyes with swollen eyelids.
Allergic cough. This cough originates from an irritated throat during allergy exposure.
Asthma or hyperreactive airway disease. In this condition, the allergen causes congestion excess mucous production ,and swelling of the lining of the bronchial tubes, while also causing spasm of the muscles around the bronchi; This combination of reactions results in cough and difficulty breathing. Asthma, which can be mild or severe, requires long term medical management to prevent complications.
Allergic gastroenteritis– This is a local reaction in the gut due to an ingested food. This reaction appears as vomiting, abdominal pain, and sometimes bloody diarrhea soon after the food is eaten.
Serous Otitis Media (Ear fluid)– Some children with chronic ear problems are allergic to foods in their diet which cause dysfunction of the Eustachian tubes, leading to ear fluid and infections.
Seasonal irritability. Some young children will be abnormally irritable during allergy seasons, even before the other symptoms develop. This is usually noted in highly allergic families. Treatment with antihistamines can restore the child to his usual happy temperament.
Anaphylaxis– This is a systemic reaction to an allergen which can be life threatening. See below for a detailed discussion of this condition.

What is an allergic reaction?

When an allergen (an allergy inducing substance) is encountered by a sensitized person, two types of inflammatory cells are activated, mast cell and basophils. These cells release a cascade of substances including histamine. Histamine causes trouble in many different areas of the body. In skin, it causes hives, itching, and dryness, as well as weeping open blisters such as poison ivy rashes. In the nose, it causes watery discharge, sneezing and congestion. In the mouth, it can cause swelling of the lips, tongue and throat. In the airway, it can cause swelling and spasm of the bronchial tree, known as asthma. In the gastrointestinal tract, it can cause vomiting, diarrhea, bleeding, or obstruction. In the cardiovascular system, it can cause severe loss of blood pressure known as shock.

Why are some people allergic while others are not allergic at all?

There is probably a genetic predisposition to developing allergies, since some families are more allergic than others. There are also environmental factors that make people become allergic more easily. If an allergen is in the environment, the specific allergy can be more common. For example, farm children are more likely to be allergic to chicken feathers.

Which foods and drugs are most allergenic?

In children, the most commonly eaten protein-containing foods are the most common allergens. These are milk, soy, egg, fish, peanuts, tree nuts, and wheat. Obviously, these nourishing foods cannot all be avoided.

When a food allergy is acute, like hives, the foods that were eaten right before the reaction are the ones to suspect. When the reaction is chronic, like runny nose, cough, chronic ear problems, or eczema, the everyday foods, like milk and soy in formula fed babies, are the ones to investigate. A doctor should be consulted to help find out what food is causing the problem.

Drug allergy

Are allergies life-long?

No. Most food allergies are outgrown within a few months of stopping the exposure. Even severe allergies can disappear over time. If the reactions are not severe or life threatening, we usually try the food again in about six months and see if it is tolerated. Severe allergies should be managed by an allergist and food “challenges” should be done under controlled circumstances, in a hospital or doctor’s office that is specially equipped. Some allergies, such as peanut, can be persistent, but not in every case.

How are allergic reactions prevented?

The issue of when to allow a baby to start eating allergenic foods is controversial. In Israel, where Bamba, a peanut flavored treat, is often given to babies, peanut allergies are very rare. In America, where most children do not eat peanut butter before 9 months of age, peanut allergy is common. The allergists are working on a reasonable plan. It may be rational to start eggs and milk products at an earlier age than was traditionally thought. Probiotics, such as Culturelle and acidophilus, have been shown to prevent the development of food allergies when given regularly.

Avoidance

Food allergens– The most effective prevention for a food allergy reaction is avoidance of the offending food once it has been identified. This allows the IgE level for this food to decrease. Since even small exposures can stimulate IgE response, it is best to completely avoid the allergy food for a few months.

Environmental allergens– For environmental allergens, such as pollens, the preventive approach is geared to minimizing exposure by having the child sleep in a dust-free room with an air purifier. During allergy seasons, it is a good idea to have the child take a shower, wash his hair and change clothes when he comes inside on a bad allergy day. This eliminates the pollen he has brought home with him.

Preventive use of medications– Sometimes, a medication must be administered continuously during allergy seasons, to prevent symptoms or keep them under control.

Desensitization– For persistent and severe environmental allergies, including severe bee sting allergy, desensitizing allergy shots, which can be given over a period of months and years, can ameliorate the problem.

What is allergy testing?

Blood tests RAST testing, which measures specific IgE levels for each suspected allergen, is done by simply drawing blood and sending it to a reliable lab. This is not very accurate if it does not show positive results in young children, since it takes until at least one year of age to get the IgeE level high enough to measure. It is very helpful if the levels are high.
Skin testing– Skin testing can be done by scratch testing or intradermal testing. It is done in a physician’s office.
Elimination diets– This method is a useful test in young children. The foods that are suspected are eliminated until the symptoms subside, and then reintroduced gradually to determine which one was the cause of the symptoms
Kinesiology and other alternative medicine testing. These procedures are not known to be based on any scientific principle. The testing is probably a sham. Their providers usually advise elimination of foods that are commonly known to be allergens.
Contact sensitivity testing. This type of test is usually done with a patch. It is used to determine which substance, such as latex, causes local symptoms when it comes in contact with skin. This is done in a physician’s office.

How are allergic reactions treated?

Here is a list of types of medications that are useful in treating allergy symptoms.

Antihistamines. These are drugs that block the effects of histamine.
The older antihistamines, such as Benedryl, Atarax, and Chlortrimaton, are stronger but they have several drawbacks. They only last about 6 hours. They can cause drowsiness, poor school performance, and dizziness. The newer antihistamines, like Claritin, Zyrtec, Allegra and their generics, are long acting and less likely to have drowsy side effects. These medications are not as powerful as the older ones. There is one antihistamine which is used in eye drops and nasal spray and has little absorption. This drug, Asteline, leaves a funny taste in the mouth after use, but it is very effective in controlling nasal symptoms. There are several antihistamine eye drops which control the symptoms of eye allergy.
Steroids. The strongest anti-allergy drug is actually cortisone. Since oral cortisone, if used for a long time, has serious systemic side effects, its use must be limited. Very high doses can be given over short periods of time to treat serious allergic problems, such as acute asthma, without serious side effects. Lately, newer forms of cortisone, such as Budesimide and Fluticasone have been invented. These are sprayed into the nose or inhaled into the airway and they have a beneficial, long lasting local effect on these areas with very little chance of systemic effects.
Cortisone creams in varying strength are used for all types of allergic skin rashes except hives. The more potent ones must be prescribed and monitored by a physician. Inappropriate use can result in permanent skin damage, and even absorption of the cortisone, causing systemic side effects.
Leukotriene inhibitors. Singulair, the only leukotriene inhibitor approved for babies and children, is a new type of drug that is effective in allergy. It works through a different mechanism than antihistamines. Instead of blocking histamine, it prevents the release of histamine. This medication has almost no side effects. It tastes delicious, and is only given once a day. It does not work during an allergy episode. Singulair works by preventing. It should be taken for two weeks prior to and then over the entire allergy season to be most effective. It is recommended for long-term use in children with recurrent wheezing, and also for seasonal nasal allergies
Epinephrine– this medication is administered by injection in an acute anaphylactic reaction.

What is Anaphylaxis?

Anaphylaxis is a severe allergic reaction that can develop very suddenly and affect every system in the body. Anaphylaxis is life threatening. It can be caused by foods, drugs, and some insect stings. Itching all over the body, hives, swelling of the tongue and throat, wheezing, feeling faint, and feeling a sense of impending doom, are all symptoms. Whenever the reaction seems to be inside the body and not just on the skin, anaphylaxis is suspected.

Anaphylaxis can cause death if it is not treated immediately. If a person of any age is having an anaphylactic reaction, he should be given three medications immediately while you are calling Hatzolah.

1) an Epipen injection, followed by oral doses of
2) Benedryl and then
3) cortisone, as quickly as possible and rushed to the emergency room. There is no time to wait and see how bad it will get. His life may depend on doing everything immediately, while you get him to an emergency room. This is really a case of “It is better to be safe than sorry.”

Epipens

Epipens are auto injectors of epinephrine that are preloaded and easily used. Epinephrine works almost instantly when it is injected into the skin anywhere on the body. Since no needle is visible, it is not scary to administer. If a child has experienced an anaphylactic reaction, the home, the car, and the school should all be supplied with Epipen juniors. Someone in each place should be trained in giving the epipen. It is not very painful at all – just a little prick -Older children and adults can easily learn to administer the epipen to themselves. There is no reason to worry about giving it by mistake. The effect is not dangerous and it can be lifesaving. Epipens should be replaced every year, since they expire.

Extreme Sensitivities

One of the hardest things to comprehend about anaphylaxis is just how sensitive a child can be to the allergen. A highly sensitive child can anaphylax from just smelling the food. As a camp doctor, I treated a fish allergic child who anaphylaxed while passing the plate of fish at the table. I have treated an egg allergic child who collapsed seconds after a drop of cake batter from the mixer splattered on his neck. I have treated a peanut allergic child who collapsed from picking up an empty wrapper from a peanut chew.

Peanut allergies can be among the most severe in children. Since the highly allergic child is really in danger from even traces of peanut in the environment, it is advised that his school be peanut free. If there is no tree nut allergy accompanying the peanut allergy, almond butter or cashew butter or pea butter are safe substitutes for peanut butter. Nosh and foods brought in from home should be carefully screened.

Over diagnosis of food sensitivity

Although food allergies are quite common, there are many children who are thought to be allergic who really are not. This mistaken perception by some parents has led to the elimination of valuable nutrients from the child’s diet. If your child has a suspected food allergy, talk to his physician about it. It may be permissible to continue giving the suspected food. Milk, eggs, nuts and fish are all nutritious components of the child’s diet.

Final thought

The extreme anxiety experienced by parents of severely allergic parents cannot be underestimated. They need a lot of support from family and friends to cope with the tensions created by the fear of anaphylactic reactions. Support groups, such as IMA in Brooklyn, have been created to network families with severely allergic children. There are new allergy diet Kosher cookbooks, such as Simply Delicious, created by Blimi Frank, a mother of a severely allergic child.

Allergies are mostly just inconveniences, and even in their most severe form, the reactions can be managed so that the child can lead a normal life. A health “para” in school is often needed to ensure that the severely allergic, anaphylactic toddler does not come into contact with the allergenic foods. The paramedic is also trained to administer the Epipen, benedryl and cortisone should a reaction occur. Fortunately, most infantile and childhood allergies lessen with time. If everyone does their share in protecting the severely allergic children in the community, both the children and the community will benefit from the consideration.

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