The Difference Between Childhood and Adult-Onset Allergies

Allergies, of any kind, are abnormal immune system responses to things usually harmless to most people. When you develop an allergy, your immune system wrongly believes that the substance involved, called an allergen, is harming your body. In response, it produces antibodies (immunoglobulin E, or IgE) which then release chemicals such as histamines that cause allergic symptoms to develop.

Somewhere around 50 million Americans, both kids and adults, have some type of allergy, with nasal allergies affecting more people every succeeding year, according to the American College of Allergy, Asthma & Immunology. That makes allergies the sixth-leading cause of chronic illness in the US, according to the CDC, at a cost of more than $18 billion a year.

At Oasis Ear, Nose, and Throat in Surprise, Arizona, board-certified otolaryngologists Dr. James Osborne and Dr. Bryan Smedley see lots of patients — both kids and adults — come in with allergies to a wide range of substances, and reactions of varying degrees. What most people don’t know, though, is that there’s a difference between childhood and adult-onset allergies, so the team has put together this guide to get you in the know.

Types of allergens and responses

Theoretically, any person can become allergic to any substance, but there tend to be some groups of allergens that are prevalent. These include:

• Airborne allergens: dust mites, pollen (trees, weeds, and grasses), molds, pet dander, and pet saliva
• Food allergens: mostly cow's milk, eggs, fish and shellfish, peanuts and tree nuts, soy, and wheat; affect up to two million, or 8%, of US kids
• Insect venom
• Medications: especially antibiotics like penicillin
• Chemicals: such as cigarette smoke, pollutants, and laundry detergent

Airborne allergens primarily cause allergic rhinitis, whose symptoms include:

• Sneezing
• Itchy nose and/or throat
• Stuffy nose
• Cough
• Itchy, watery, and/or red eyes (allergic conjunctivitis)

Most airborne allergies develop by age 10, peak in the teens or early 20s, and often disappear between 40 and 60.

Food, medicine, or insect allergy symptoms can include:

• Wheezing and difficulty breathing
• Coughing
• Throat tightness and hoarseness
• Stomachache, vomiting, and diarrhea
• Itchy, watery, or swollen eyes
• Hives
• Decreased blood pressure, leading to lightheadedness or loss of consciousness

Every person’s specific response varies, and a mild reaction at one time doesn’t necessarily mean future reactions will be mild. In some cases, a severe, life-threatening response called anaphylaxis can occur. It can be reversed by administration of epinephrine, which reduces swelling and increases blood pressure.

Childhood allergies

Children often inherit the tendency to develop allergies, though not necessarily a particular allergy, which means their developing immune systems can kick into overdrive any time the child’s exposed to an allergen. Most often, it’s to a new food. However, some kids develop allergies even if no other family member is allergic, and kids who have allergies to one substance are likely to develop allergies to others.

The most common childhood allergies are to peanuts and cow’s milk. The most severe reactions usually come from peanuts, tree nuts, fish and shellfish — all allergies that may last their entire lives. In contrast, children often outgrow allergies to milk, eggs, soy, and wheat.

Adult-onset allergies

You can develop an allergy at any point in your life, even to something you had no allergy to before. It isn’t clear why that should happen, especially since your immune system naturally weakens as you age, and therefore isn’t as aggressive as it was when you were a child. Researchers believe that a severe childhood reaction, even just once, can increase your likelihood of developing allergies later on, when you’re re-exposed to that allergen at higher levels. However, that’s clearly not the whole story.

Nearly 11% of US adults have some type of food allergy, and almost half report first noticing symptoms during adulthood, especially to certain kinds of fish. Other common food allergens are peanuts, tree nuts, and fruit and vegetable pollen.

Possible adult allergy triggers include:

• Exposure during reduced immune system function: when you’re sick, pregnant, or have a compromised immune system
• Having little exposure to an allergen as a child: not exposed to high enough levels to trigger a reaction until adulthood; common in highly sanitized Western countries
• Moving to a new home or workplace: with new allergens you weren’t exposed to before
• Having a pet for the first time or getting a different kind of pet (dander)

Whether your child has an allergy or you’re first noticing a reaction as an adult, there are treatments including antihistamines, allergy shots, and the EpiPen® that can make your allergies more manageable and your life more comfortable. Give Oasis Ear, Nose, and Throat a call at 623-234-4640 to schedule a consultation, or book your appointment online today.