Allergies are dynamic conditions that change throughout a person’s life, meaning there is no single answer to whether they fade or worsen with age. An allergy is an overreaction of the immune system, which mistakenly identifies a normally harmless substance, like pollen or a food protein, as a threat. This misidentification triggers the release of chemicals, such as histamine, leading to symptoms like sneezing, itching, or swelling. How these immune responses evolve depends on genetics, environmental exposure, and the natural maturation of the body’s defenses.
Allergies That Often Fade in Childhood
Many food allergies that develop early in life have a high likelihood of resolving as a child grows. This phenomenon of “outgrowing” an allergy is most common with certain food proteins. Approximately 80% of children with allergies to milk or egg will become tolerant by adolescence. The probability of resolution is significantly higher for the common pediatric allergies of milk, egg, wheat, and soy. Studies show that milk allergies resolve in over half of affected children by the age of five, with the chance of tolerance improving steadily through late childhood. The development of immune tolerance is a gradual process tied closely to the maturation of the gastrointestinal tract and overall immune system regulation.
Allergies That Typically Persist or Appear Later in Life
In contrast to the transient nature of many childhood food sensitivities, other types of allergies tend to be lifelong or may emerge for the first time in adulthood. Allergies to peanuts, tree nuts, and shellfish are far more likely to persist. Only about 10 to 20% of children with peanut or tree nut allergies will outgrow them.
Environmental allergies, such as those to pollen, dust mites, and mold, are also generally persistent once established. Symptoms of allergic rhinitis, or hay fever, can develop in adulthood, sometimes with a first onset even after the age of 50. New allergies can appear unexpectedly, with nearly half of food-allergic adults reporting that at least one of their food allergies began after the age of 18. Common adult-onset food allergies often involve shellfish, tree nuts, and certain fruits due to cross-reactivity with pollen.
Understanding Why Allergies Change Over Time
The shifting landscape of allergic disease is rooted in the dynamic nature of the immune system and its interaction with the environment. Immune system maturation plays a significant part, especially in childhood, where the developing body learns to differentiate between harmful pathogens and harmless proteins. For some allergens, the immune system eventually shifts away from an exaggerated response—characterized by the antibody Immunoglobulin E (IgE)—to a state of tolerance.
This shift is a key reason why many young children lose their allergies to foods like milk and egg. The body stops producing the specific IgE antibodies that trigger allergic reactions upon exposure. Conversely, the immune system can become newly sensitized to a substance at any point in life, leading to the development of adult-onset allergies.
New sensitization in adulthood is often linked to changes in exposure or cumulative effect. Moving to a new geographic region introduces different types of pollen, requiring a person’s immune system to encounter new allergens. It can take several seasons of exposure to a new regional pollen for the immune system to build up enough IgE to trigger noticeable symptoms.
The Atopic March
The concept known as the “atopic march” illustrates the typical progression of allergic conditions over a lifetime. This pattern often starts with atopic dermatitis, or eczema, in infancy, followed by the development of IgE-mediated food allergies, which then may progress to allergic rhinitis and asthma later in childhood. This progression is thought to be driven by a disrupted skin barrier in eczema, which allows allergens to enter the body and trigger sensitization. Environmental factors, including air quality, infection history, and lifestyle, also constantly modulate the immune system’s baseline reactivity, influencing whether an existing allergy worsens or a new one emerges.