Allergies in Children: Common Symptoms, Treatment, and When to Seek Emergency Care

First: recognizing anaphylaxis—a medical emergency

Anaphylaxis is a severe, rapid allergic reaction that can be life-threatening. It can happen without hives or a visible rash.

A small amount of isolated lip or facial swelling does not always mean anaphylaxis. It still needs close attention because reactions can progress. Follow the action plan and seek medical advice; do not wait if severe symptoms or symptoms in another body system appear.

Epinephrine is the first and most important treatment. When an auto-injector is prescribed, it is used in the outer thigh according to the device instructions. Make sure caregivers know how to use the specific epinephrine product your child has been prescribed.

Antihistamines can help mild symptoms such as itching, but they do not treat breathing or blood-pressure problems and are not a substitute for epinephrine.

After using epinephrine for suspected anaphylaxis, a child still needs emergency evaluation, because symptoms can sometimes return hours later.

If your child has been prescribed epinephrine auto-injectors, keep two available at all times, make sure caregivers and the school know how to use them, and check expiration dates.

Common allergic and related conditions

Several conditions often occur together, but they are not all simply reactions to a particular allergen:

• Eczema (atopic dermatitis): An itchy, dry, bumpy rash that often shows up in the first months of life. It tends to appear on the cheeks and scalp in babies, and in the elbow and knee creases in older children. Eczema involves problems with the skin barrier and inflammation; it is not usually caused by a specific food allergy.
• Food allergy: Immediate, IgE-mediated food reactions can cause hives, vomiting, swelling, or trouble breathing, usually within minutes to 2 hours after eating a particular food. Other types of food allergy can cause delayed symptoms.
• Seasonal and year-round nasal allergies (allergic rhinitis, or hay fever): Sneezing, runny or stuffy nose, and itchy, watery eyes triggered by pollen, dust mites, mold, or animals.
• Asthma: Coughing, wheezing, or trouble breathing. Allergies can trigger asthma symptoms, but asthma also has nonallergic triggers, such as respiratory infections, smoke, and cold air.

Allergies also tend to run in families. A child with one allergic condition, or with close relatives who have allergies, asthma, or eczema, is more likely to develop others.

The allergic march

Eczema, food allergy, nasal allergies, and asthma can develop together or at different ages. Eczema and food allergy often appear in infancy, while nasal allergies and asthma may become apparent later. This pattern is sometimes called the allergic march.

It is not an inevitable or fixed sequence. Many children do not develop all of these conditions, and some conditions improve with age. Early, severe eczema is a reason to discuss food-allergy prevention with your pediatrician—not a prediction that your child will develop every allergy.

Food allergies

Common food allergens include peanut, tree nuts such as cashew and walnut, milk, egg, soy, wheat, fish, shellfish, and sesame. Milk, egg, and peanut allergies are common in babies and toddlers; the pattern of food allergies can change as children grow.

How food allergy is diagnosed

Diagnosis is based on the story of what happened combined with testing—not on testing alone.

A skin-prick test or a blood test can show whether a child's immune system is sensitized to a food, but a positive test by itself does not prove a true allergy. The size of a test result does not reliably predict how severe a reaction would be.

Many children are best evaluated by an allergy specialist. Sometimes a carefully supervised oral food challenge—eating small, increasing amounts of the food under medical supervision—is needed to know for sure. Do not attempt a food challenge at home for a suspected or known allergy unless your child's clinician has specifically directed it.

A caution about avoiding foods

Cutting many foods out of a child's diet based only on positive tests, without a clear history of reactions, can lead to poor nutrition and unnecessary stress. In some circumstances, unnecessary avoidance can also increase the risk of developing a food allergy. Any major dietary elimination should be guided by a clinician.

Managing a known food allergy

The main steps are avoiding the food, reading ingredient labels carefully, teaching caregivers and schools, and keeping prescribed emergency epinephrine available. Your allergist can discuss whether additional treatments are appropriate for your child.

Nasal allergies (allergic rhinitis)

Nasal allergies can affect sleep, school performance, and quality of life, and can worsen asthma. Signs include sneezing, a runny or blocked nose, throat clearing, cough, and itchy, watery eyes. Some children rub their nose upward or have dark circles under their eyes.

Helpful steps include:

• Reducing exposure to known triggers: For example, keeping windows closed during high pollen counts, using dust-mite-proof covers on mattresses and pillows if a child is allergic to dust mites, and managing pet exposure.
• Saline: An age-appropriate saline spray or rinse may help remove allergens and mucus. Ask your pediatrician which method is appropriate for your child.
• Medications: Second-generation antihistamines such as cetirizine, loratadine, or fexofenadine can help milder symptoms. They are generally less sedating than older antihistamines, although some children still become sleepy. Steroid nasal sprays are often the most effective option for ongoing, moderate-to-severe nasal symptoms. Ask your pediatrician about the right product, technique, and dose for your child's age.

When allergy immunotherapy may help

For children whose symptoms are not controlled with these measures, an allergist may recommend allergy immunotherapy: allergy shots or, for selected allergens and ages, FDA-approved under-the-tongue tablets.

Liquid allergy drops are not FDA-approved in the United States. They are different from the approved tablets.

Immunotherapy can reduce sensitivity to specific allergens and may provide lasting symptom improvement. Treatment usually takes several years. Researchers are also studying whether it lowers the risk of developing asthma, but the evidence is mixed.

Eczema care

Good eczema care helps protect the skin barrier and control itching and inflammation:

• Moisturize generously and often with a fragrance-free cream or ointment, especially right after bathing.
• Avoid irritants such as harsh soaps, fragranced products, and known triggers.
• Use prescribed anti-inflammatory treatments such as topical steroids or non-steroid creams during flares, as directed.
• Antihistamines do not clear eczema, though a doctor may occasionally recommend one for a specific reason during a difficult flare.

Eczema care is important in its own right. Researchers are still studying whether treating eczema prevents later food allergies. Routine moisturizing has not been established as a way to prevent food allergy.

Preventing food allergies: early introduction

Delaying allergenic foods does not prevent food allergy. Introducing peanut and well-cooked egg early, in developmentally appropriate forms, can help lower the risk of allergy to those foods.

• For most babies: Introduce common allergenic foods when your baby is developmentally ready for solids, generally around 6 months. Do not start solids before 4 months.
• For babies with severe eczema or a known egg allergy: Talk with your pediatrician or an allergist early. Peanut introduction may be recommended as early as 4 to 6 months, once the baby is ready. Testing or a supervised first feeding may be advised.
• Use infant-safe forms: Offer well-cooked egg and smooth peanut butter thinned into a familiar purée or another appropriate food. Never give whole nuts or thick globs of peanut butter, which are choking hazards.
• Keep offering tolerated foods regularly once introduced, rather than giving them once and stopping.
• There is no reason to deliberately delay other common allergenic foods once your baby is ready for them.

If your baby has already reacted to a food, ask your clinician before offering it again. Early introduction is a prevention strategy, not a home treatment for an established food allergy.

When to see a doctor

Contact your pediatrician if your child has:

• Recurrent hives, swelling, or reactions after eating
• Eczema that is hard to control
• Nasal or eye symptoms that disrupt sleep, school, or daily life
• New or recurrent wheezing
• A family history of allergies and questions about introducing allergenic foods

Breathing difficulty needs prompt assessment, not a routine appointment. For suspected anaphylaxis, follow the emergency instructions above. For severe breathing difficulty, collapse, or a child who cannot be awakened, call 911.

Key takeaways

• Childhood allergies and related conditions often overlap and frequently run in families.
• A true food allergy is diagnosed using the reaction history and appropriate testing; a positive test alone can be misleading.
• Know the signs of anaphylaxis. Give prescribed epinephrine promptly and call 911 when anaphylaxis is suspected.
• Nasal allergies are treatable. Trigger reduction, saline, appropriate antihistamines, and steroid nasal sprays can help.
• Good eczema care controls skin symptoms, but it is not a guaranteed way to prevent other allergies.
• Timely introduction of peanut and well-cooked egg can help prevent food allergy. Babies with severe eczema or egg allergy need an early discussion with their clinician.