Allergies represent an immune system overreaction to substances typically harmless to most individuals. These substances, known as allergens, include pollen, dust mites, certain foods, or pet dander. When an allergic person encounters an allergen, their immune system mistakenly identifies it as a threat, producing antibodies that trigger reactions and various symptoms. While some allergies can diminish or disappear over time, this process is complex and depends on the type of allergy, the individual’s immune response, and medical interventions. Symptoms can fluctuate throughout a person’s life, sometimes lessening in severity or becoming more pronounced.
Natural Outgrowing of Allergies
Allergies naturally resolving is particularly observed in childhood, especially with certain food allergies. Many children outgrow allergies to milk, egg, soy, and wheat. For instance, research indicates that around 90% of infants with egg allergy may outgrow it by age six, with milk allergy showing similar positive outcomes. This natural resolution is linked to the developing immune system learning to tolerate these previously allergenic foods.
However, not all food allergies follow this pattern. Allergies to peanuts, tree nuts, fish, and shellfish are considerably less likely to be outgrown and often persist. Approximately 20% of children with a peanut allergy may outgrow it, while for tree nuts, this figure can be as low as 9-14%. Shellfish and fish allergies are often lifelong. Environmental allergies, such as those to pollen or dust mites, can sometimes lessen in severity, but complete natural resolution is less common than with certain childhood food allergies.
Therapeutic Paths to Allergy Tolerance
Medical interventions can induce tolerance or significantly reduce allergy severity through allergy immunotherapy (AIT). AIT works by gradually exposing the immune system to increasing amounts of the allergen. This systematic exposure desensitizes the immune system, encouraging tolerance to the allergen rather than a reaction. Immunotherapy induces long-term changes in the immune response, going beyond symptom management.
Two primary forms of AIT are used for environmental allergies. Subcutaneous immunotherapy (SCIT), known as allergy shots, involves regular injections of allergen extracts, given over three to five years. This method can treat multiple allergens simultaneously and is the only treatment proven to prevent new allergies or the progression of allergic diseases like asthma. Sublingual immunotherapy (SLIT) involves placing tablets or drops containing allergens under the tongue, offering a needle-free alternative. SLIT is FDA-approved for specific allergens like grass and ragweed pollens and dust mites.
For food allergies, Oral Immunotherapy (OIT) is another approach to build tolerance. OIT involves consuming gradually increasing doses of the specific food allergen under strict medical supervision. OIT aims to increase the amount of allergen a person can tolerate without a reaction, offering protection against accidental exposures. While not a cure, OIT can desensitize individuals, making accidental ingestion less dangerous. All forms of immunotherapy require professional supervision due to the risk of allergic reactions during treatment.
When Allergies Persist
Despite natural resolution and therapeutic interventions, some allergies persist throughout life. Certain food allergies, particularly those to peanuts, tree nuts, fish, and shellfish, often remain chronic. Similarly, chronic environmental allergies to substances like pollen, dust mites, or pet dander can endure for many years. The immune system retains a “memory” of these allergens, meaning the underlying sensitivity remains, even if symptoms fluctuate.
For persistent allergies, management focuses on minimizing symptoms and preventing severe reactions rather than achieving complete resolution. Avoidance strategies are fundamental, including limiting exposure to known allergens, using air filters, or washing bedding regularly. Emergency medications, such as epinephrine auto-injectors, are prescribed for individuals at risk of severe reactions like anaphylaxis. Symptom-relief medications, including antihistamines and nasal sprays, help manage daily discomfort. These strategies improve quality of life and reduce the impact of allergies, differing from inducing immune tolerance.