Allergies & Children – Causes, Signs and symptoms

Allergies Children

Also called: Childhood Allergies


Childhood allergies are a common and growing problem in the United States. In recent years, the number of children with allergies to food, pollens, latex and other allergens has grown dramatically. There has also been a surge in the number of children with asthma, and other allergic conditions, such as the skin disorders contact dermatitis and eczema.

The exact reason behind the rise of allergies in children is unknown. But a growing body of evidence suggests that a combination of genetic and environmental factors is at the root of most childhood allergies.

Armed with that knowledge, healthcare professionals can use drug therapy and suggest lifestyle changes to successfully treat most childhood allergies.

There are a number of differences in how allergies affect children versus adults. These include:

  • Types of allergies. Some allergies (e.g., food allergies) are more common in children than adults, while others (e.g., seasonal allergies) are less common.
  • Signs and symptoms. Children and infants may experience symptoms of allergies differently than adults.
  • Diagnosis methods. Certain tests used in diagnosing allergy causes may not be appropriate for children.
  • Treatment options. Some medications used to treat allergies in adults are too strong for children. In addition, side effects of medications are often different in children than in adults.

Children with asthma may also need careful allergy management, since many of the same allergens that trigger allergies also provoke asthma symptoms.

About allergies & children

Allergic reactions work the same in children as they do in adults. An allergic reaction is the immune system’s attempt to defend the body from a perceived threat that, in reality, is harmless. During this process, a foreign substance called an antigen comes into contact with the body. The immune system responds to the perceived threat of the antigen by producing protective proteins called antibodies.  

Each antibody is specifically designed to recognize a particular antigen. The antibody that responds to allergens is called immunoglobulin E (IgE). The antibody is attached to a mast cell, which contains granules of histamines and other chemicals. When the antibody binds to the allergen, the mast cell releases histamines and other chemicals, which trigger an allergic reaction. This produces symptoms such as itchy eyes, runny nose and sneezing. In some cases, the reaction is more extreme, resulting in hives, eczema (skin inflammation) or breathing difficulties.

While all humans have stores of IgE, allergic individuals produce the antibody in much greater amounts. To make matters worse, increased exposure to the allergen causes higher production of the IgE antibody in the individual, causing greater sensitization to the allergen with each additional exposure. This sets the stage for more frequent and increasingly severe future reactions to the allergen.

Childhood allergies provide the foundation for many of the allergic problems that people will experience throughout their lifetime. While some people outgrow their childhood allergies, many will see their symptoms escalate into adulthood.

Some allergies tend to afflict children more than adults. For example, children are more likely to have food allergies than adults. Conversely, children are less likely to have seasonal allergies because they have not yet lived long enough to be sensitized to many of these allergens. Over time, however, they can develop many of these allergies with increased exposures.

According to the American Academy of Allergy, Asthma and Immunology (AAAAI), allergy symptoms result in about two million missed school days each year. Children with allergies may have trouble sleeping due to nasal congestion. This may cause drowsiness that impacts their ability to learn and play. Studies also have shown that children with allergies are more likely to become aggressive, depressed and irritable.

Untreated, severe nasal congestion can – in some cases – lead to more serious complications. A child who must breathe constantly through the mouth can develop a facial pattern called adenoidal face, in which the face becomes elongated due to the impact force of air on the mouth’s soft bones. This may cause the teeth to grow in at an improper angle, as well as causing an overbite.

Allergy symptoms can also cause fluid to build up within the ear, affecting hearing and leading to frequent ear infections. This can impact speech development, and may require the insertion of ear tubes.

Many of the same allergens that trigger allergies also provoke symptoms in those who have asthma, a chronic inflammation of the airways that makes breathing difficult. These include pollens, molds, pet dander, perfumes and more. Therefore, allergy management is an important part of asthma management in children.

Types and differences of allergies in children

Children generally are vulnerable to many of the same allergies that afflict adults. However, a child’s likelihood of reacting to certain allergens differs from adults. Allergies that affect children include:

  • Food allergies. Children experience these at a much higher ratio than adults, with those under age 3 showing the highest incidence of allergic reactions. Up to 8 percent of children have a food allergy as compared to roughly 2 percent of adults, according to the American Academy of Allergy, Asthma and Immunology (AAAAI). High-protein foods are particularly likely to trigger symptoms. Foods often associated with food allergies include:
    • Milk
    • Eggs
    • Wheat
    • Peanuts
    • Soy beans
    • Shellfish
    • Tree nuts (such as walnuts)
    • Corn
    • Sesame seeds
  • Allergic rhinitis (hay fever). Young children experience these allergies at a lesser rate than teens and adults. Dander, dust mites and molds are among the first allergens to affect children. As children grow, they are likely to be exposed to an ever-growing list of pollens and other allergens that may eventually trigger allergies. A child’s allergic rhinitis symptoms mimic the typical adult reaction, and include sneezing, wheezing and watery eyes.
  • Eczema. This is a type of skin rash that most often occurs in infants and young children. Eczema tends to run in families and appears to be related to food allergies, although it is caused by both genetics and environmental factors, and a specific aEczema is an inflammatory skin disease with lesions that appear dry, thickened or scaly.llergen is not necessarily involved. Eczema is triggered by many different factors, including allergies, temperature, humidity and stress. However, a given trigger may not affect a given patient. A significant number of patients with eczema, for example, do not have any food allergies. About 90 percent of cases occur in children under the age of 5, according to the AAAAI. The affected area has a red, scaly, itchy rash. Eczema can indicate that a child is more prone to developing other allergies later in life.
  • Animal allergies. Pets are the prime source of animal allergies for children. Cats and (to a lesser degree) dogs trigger reactions due to the protein allergens secreted by oil glands in their skin and shed Dander. Proteins in animal urine and saliva (particularly if an animal frequently licks itself) also trigger allergies.
  • Insect stings. Children may also be allergic to the saliva or venom in some insects’ bites and stings. In some cases, the symptoms produced by a sting are life–threatening (anaphylactic shock). Honeybees are the only insects that leave a stinger in their victims (which must then be carefully removed).
  • Contact dermatitis. Allergic reactions on the skin caused by any natural or manmade material. Latex is one such material to which some children (and adults) are allergic. Some infants are allergic to the dye found in some diapers.

Potential causes of allergies in children

A combination of genetic and environmental factors causes allergies in children. Genetics play a powerful role in determining a child’s predisposition to allergies. According to the Asthma and Allergy Foundation of America (AAFA), a child has about a 50 percent chance of developing allergies if one parent is allergic. The odds jump to 75 percent when both parents have allergies. However, parents and children do not necessarily share the same allergies, and some children with highly allergic parents remain symptom-free.

While genetics may predispose a child towards allergies, it is environmental factors that trigger the allergy itself. An allergic reaction cannot occur the first time a child is exposed to a potential allergen – instead, there must be a period of sensitization where the immune system produces its initial antibodies to the antigen. Once this process takes place, an allergic reaction is primed to occur the next time the child is exposed to the allergen.

Environmental factors also are at the root of a theory that seeks to explain why more children suffer from allergies and asthma today than in the past. A growing body of evidence supports the notion that childhood allergies and asthma have increased as society has placed a greater emphasis on cleanliness.

According to the so-called “hygiene hypothesis,” today’s children are too insulated from bacteria and other agents that cause infections. This has retarded the development of their immune systems, putting them at greater risk for becoming allergic or asthmatic, according to the theory.  However, this theory remains in dispute and research is ongoing.

Signs and symptoms of allergies in children

Symptoms of allergies in children largely mimic those of adults. However, parents should be aware that children – especially younger children – cannot always communicate the nature of what they are experiencing. Therefore, parents must watch carefully for the signs and symptoms of allergies, including:


  • Labored breathing
  • Stuffy nose
  • Recurring ear infections (otitis media)
  • Skin rashes (especially on cheeks, behind ears or on thighs)
  • Colic (repeated, prolonged episodes of intense crying for no apparent reason)
  • Diarrhea or vomiting
  • Excessive drooling, spitting or perspiration
  • Eczema (a skin condition often exacerbated by food allergies)


  • Trouble breathing
  • Wheezing
  • Sneezing
  • Chronic sore throat or nasal congestion
  • Rubbing the nose excessively (allergic salute)
  • Diarrhea or constipation
  • Vomiting
  • Stomach cramps
  • Ear and nose infections
  • Tiredness and irritability
  • Eczema, hives or other skin conditions
  • Breathing through the mouth (particularly while sleeping)
  • Itchy, watery and/or red eyes
  • Puffy eyes
  • Changes in behavior

It is important to note that the type and severity of allergy symptoms will vary from child to child and allergy type to allergy type, as well as from year to year and from exposure to exposure in a given child. Symptoms can be minor or severe. They can also appear year-round or just during certain times of the year.

In rare cases, a child’s allergic reaction may take the form of anaphylaxis, a potentially life-threatening condition that involves two or more body systems. Anaphylaxis usually develops rapidly and demands immediate, emergency medical attention. The condition can quickly progress to life-threatening anaphylactic shock, which is characterized by difficulty breathing and a dangerous drop in blood pressure. Seek immediate medical care after observing the following signs and symptoms:

  • Severe itching of the eyes and face
  • Feelings of anxiousness
  • Palpitations (an awareness of a strong, fast, irregular, abnormal or “galloping” heartbeat)
  • Slurred speech
  • Inability to swallow
  • Swelling of the throat or tongue
  • Rapid or weak pulse
  • Red or swelling skin
  • Nausea or vomiting
  • Severe wheezing or coughing
  • Bluish tint to skin (cyanosis), including lips or nail beds
  • Choking or shortness of breath

Diagnosis methods for allergies in children

An allergy skin test is the preferred method for pinpointing which allergens are causing an allergic reaction. However, these tests raise special concerns for children who fear needles or who may become alarmed at the raised bumps that generally signal a positive reaction. Parents and healthcare providers must be sensitive to these fears and ready to offer the support necessary to help a child successfully complete testing.

During an allergy skin test, the child’s arm or back is marked with an ink pen – each mark corresponds to an allergen. Tiny amounts of the allergen are then introduced to the appropriate spot marked on the child’s skin by one of two methods:

  • Epicutaneous testing. The allergen is introduced just barely below the surface of the skin by either a prick, scratch or patch method.
  • Intradermal testing. The allergen is injected below the skin with a needle and syringe.

A period of at least 15 minutes then passes before the child is examined for positive reactions to any of the allergens. If a raised bump (similar to a mosquito bite) appears, it is likely the child is allergic to that allergen.

Although most children do not find allergy testing to be painful, they are likely to feel some discomfort both during and after the process. Itching and redness at the puncture sites are not unusual. Parents should prepare their child for these likely side effects. A cool, wet cloth often can relieve some of the discomfort caused by itching.

For some children, allergy skin tests are not a practical option. This is particularly true for those with certain skin diseases (e.g., eczema, hives). In such cases, a physician might recommend radioallergosorbent (RAST) testing. This blood test detects immunoglobulin E  (IgE) antibodies for particular antigens. Though the test misses some allergies, it is a valuable testing option.

An elimination diet may be recommended when a food allergy is suspected. This diet involves removing suspect foods from a child’s diet to see if allergic reactions persist.

Parents also can contribute to an accurate diagnosis by keeping a diary of their child’s allergy symptoms. The diary should include the following circumstances surrounding the appearance of symptoms:

  • Time, date and location
  • Foods eaten recently
  • Pollen count and mold count
  • Recent exposure to animals
  • Recent activity (e.g., playing outdoors, visiting a farm)

Treatment options for allergies in children

There are many over-the-counter antihistamines and decongestants for sale in formulations designed for children with mild allergy symptoms. However, these may have side effects for the child, such as hyperactivity or sedation. Parent should consult with a physician or healthcare provider before giving children any allergy medication, even over-the-counter (OTC) varieties. It is also important never to give children medications designed for adult use without specific instructions from a physician.

Prescription medications may be necessary for children with moderate to severe allergies. Those approved for limited use in children include:

  • Antihistamines. Medications used to treat allergy symptoms such as sneezing, runny nose and itchy and watery eyes. Cetirizine and desloratadine have been approved for children over 6 months of age, and loratadine for children over 2. Fexofenadine hydrochloride has been approved for ages 6 and up. Antihistamines work by neutralizing the histamines that are released in the bloodstream during an allergic reaction. Antihistamines can reduce symptoms when taken after the allergic reaction begins. However, they are most effective when taken 3 to 5 hours before coming into contact with an allergen.
  • Leukotriene modifiers. Medications used to prevent both nasal allergy symptoms and asthma-related symptoms. Montelukast has been approved for children over the age of 1. Leukotriene modifiers are effective when used prior to an allergic reaction because they work to disrupt a specific chemical process in the allergic cascade, preventing some types of leukotriene from forming in the body. These medications are primarily used in the prevention of asthma-related symptoms, but are finding increased use for allergies.
  • Steroid nasal sprays. Medications used to reduce the inflammation associated with symptoms such as nasal stuffiness, sneezing and runny nose. Mometasone furoate monohydrate has been approved for ages 2 and up and fluticasone propionate for ages 4 and up. These medications are most effective when taken daily and often require one to two weeks of use before reaching their full effect.
  • Mast cell stabilizers. Medications effective at treating mild or moderate inflammation in the bronchial tubes as well as sneezing, watery eyes and congestion. Cromolyn sodium may be prescribed in nasal spray form for some children. Mast cell stabilizers prevent mast cells from releasing histamine and other chemicals that can cause allergy symptoms.
  • Epinephrine. Epinephrine (allergy kit) is used to immediately treat the most severe allergic reactions involving the potentially life-threatening condition known as anaphylaxis. Epinephrine is a synthetic form of adrenaline that, when injected, works as a powerful bronchodilator, opening breathing tubes and restoring normal respiration quickly. Most physicians recommend that children who are susceptible to severe reactions carry an injection of epinephrine with them at all times and understand how to self-administer the drug. In the case of infants or young children, anyone watching or supervising the child should have immediate access to an epinephrine shot, as well as know how to properly administer the drug.

The above medications address the symptoms associated with allergies in children. The only treatment currently available for addressing the underlying allergic condition is immunotherapy (allergy shots). By using this method, a child can gradually become more tolerant to a specific allergen(e.g., a specific pollen, latex) over a period of years.

During immunotherapy, tiny amounts of an allergen are injected under the patient’s skin over a period of years. With each shot, the amount of allergen is increased. Over time, the patient’s tolerance level to the allergen rises dramatically, causing a significant reduction in symptoms such as runny nose, itchy eyes and scratchy throat. 

Allergy shots are not always effective and they may not be recommended for children with certain allergies (e.g., food allergies). Administering this therapy safely in children is also more challenging, because young children are not always able to communicate signs of a potential reaction to a physician. Younger children also have smaller respiratory reserves, which also puts them at greater risk of respiratory side effects. Therefore, most health professionals will not prescribe immunotherapy for children under 5.

Prevention methods for allergies in children

Parents seeking to reduce their children’s risk of developing an allergic condition may find themselves trying to sort through a mass of contradictory advice. For years, experts have urged parents to shield infants from frequent and intense exposures to potential allergens. It has been argued that doing so reduces the likelihood that a child will develop certain allergies.

While this is still the commonly held view, some new evidence contradicts the theory. For example, recent studies have found that young children who grow up around pets are actually less likely to develop allergies to animal dander. These findings conflict with the long-held conviction that kids exposed to pets are more likely to develop animal allergies.

Similar contradictions are evident elsewhere. For example, some studies indicate that breastfeeding lowers the likelihood of child allergies and asthma, while others suggest that breastfeeding increases the incidence of those conditions. Research has suggested that breast milk provides some protection, but that IgE antibodies may pass to the child, which may make a child more susceptible to allergies or asthma later in life.

However, the medical consensus is that the overall benefits of breastfeeding to the child’s development outweigh the potential negatives. Parents with questions should consult their physician.

The advice is much clearer about how to prevent symptoms of an already existing condition. The best way to protect children already diagnosed with allergies or asthma is to limit their exposure to allergens and triggers to the greatest extent possible.

Parents should take the following steps based on their child’s allergy:

  • Seasonal allergies. Airborne allergens are a major trigger for allergic rhinitis (hay fever) and asthma, so limiting exposure to pollens and molds will likely reduce symptoms in children. Parents are urged to:
    • Avoid having carpet in dark, damp rooms that can be a breeding ground for mold
    • Keep indoor humidity below 50 percent by using air conditioning or a dehumidifier
    • Keep windows closed and children indoors when pollen counts are high
    • Encourage participation in indoor sports where pollens and molds are less of an issue (e.g., swimming, basketball, hockey, indoor volleyball)
  • Dust allergies. Although there is no way to completely eliminate exposure to either dust or dust mites, there are several steps parents can take to reduce their child’s exposure to the allergens, including:
    • Contain or kill dust mites by using zippered, plastic covers on pillows, mattresses and box springs
    • Wash bedding, curtains and rugs frequently in hot water (at least 130 degrees Fahrenheit [54 degrees Celsius])
    • Keep carpets, upholstered furniture and objects that collect dust (e.g., stuffed animals, drapes) out of a child’s bedroom
    • Dust frequently with damp or oiled cloths to keep dust from spreading
  • Food allergies. Most experts believe that a mother’s milk is the best source of nourishment for a child. If a baby has an allergic reaction during breastfeeding, a change in the mother’s diet may be warranted. Alternatives such as soy-based formulas can be given to babies who react to standard milk-based baby formula.

    Experts suggest the following for reducing a child’s risk of developing a food allergy:
    • Introduce a child to solid foods slowly. Start with small amounts of apples, bananas, pears, sweet potatoes, white potatoes, rice and other foods that do not typically cause reactions.
    • Initially, avoid wheat, eggs, corn products and nut butters. When you do try them, do so in small amounts and watch for any symptoms of an allergy (including hives, wheezing, or swelling of the lips, tongue or face).

Parents of children with food allergies can reduce the risk for allergic reactions by carefully checking food labels for problem ingredients and learning any alternate names a dangerous food may be listed under. When the child is old enough they should be taught how to do this as well. In addition, parents of allergic children should always inquire about cooking techniques and ingredients at restaurants. Parents should also alert their child’s school to the allergies. 

  • Animal allergies. Proteins in animal dander, urine and saliva are the chief source of allergic symptoms for those with animal allergies. Many of these allergens come to rest in carpets and furniture, where they can remain for four to six weeks. Allergens that become airborne can remain that way for months after an animal is removed from a home. Tips to prevent symptoms related to animal allergies in children include:
    • Follow tips associated with Seasonal allergies, which are also caused by airborne allergens
    • Consult with a landlord or a home’s previous occupant about pet history before moving in
    • Find the family pet a new home
  • Contact dermatitis. Any material that causes an allergic reaction should be avoided. One such possible allergen is latex (a milky sap derived from the rubber tree), which is used to produce many products, including rubber bands and bandages. Parents whose children have latex allergies should avoid having these products in their homes.

It also is important for parents to inform child–care and school staff of their child’s allergy, so proper precautions can be taken. For example, cafeteria workers can wear vinyl gloves instead of rubber gloves to prevent a reaction in a child with a latex allergy, and special meals can be prepared for children with food allergies.

In addition, it is important that parents limit their children’s exposure to tobacco smoke. Pregnant women who smoke and parents who expose children to secondhand tobacco smoke dramatically increase the likelihood of child respiratory ailments. Tobacco smoke also triggers symptoms related to already–existing respiratory conditions, such as asthma.

Questions for your doctor

Preparing questions in advance can help parents to have more meaningful discussions with their child’s physicians. Parents may wish to ask their child’s doctors the following questions regarding allergies and children:

  1. I suffer from allergies. Does this make my child more likely to develop them?
  2. Do my child’s symptoms suggest an allergy?
  3. What tests will you use to determine the trigger of my child’s symptoms?
  4. Do allergies pose a danger to my child’s overall health?
  5. What are my child’s chances of outgrowing the allergy?
  6. What treatments are available to my child?
  7. Is my child a candidate for allergy shots?
  8. What side effects may my child develop from taking allergy medication?
  9. What steps can I take to lower my child’s risk of having a reaction?
  10. Is my child likely to experience symptoms year-round or just at certain times of year?
  11. What symptoms should I immediately report to you?
  12. What may have caused my child to develop allergies?
  13. Are my other children also likely to develop allergies?
  14. Are there steps I can take to lower my child’s risk for developing allergies?
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