Adults can develop new allergies, even if they’ve never experienced them before. Adult-onset allergies can manifest in various forms. Understanding how these allergies emerge helps in recognizing and addressing them.
How Adult-Onset Allergies Develop
The development of allergies in adulthood involves complex interactions within the immune system. The immune system can become sensitized to new allergens, mistakenly identifying harmless substances as threats. This process leads to the production of specific antibodies, called immunoglobulin E (IgE), which then trigger an allergic reaction upon subsequent exposure by releasing chemicals like histamine.
Changes in a person’s environment or lifestyle often introduce new allergens. Moving to a different region with distinct plant life, acquiring a new pet, or experiencing shifts in dietary habits can expose the immune system to new substances. Sometimes, it can take a few years of consistent exposure to an allergen before symptoms begin to appear.
Cross-reactivity, where the immune system reacts to substances structurally similar to known allergens, also plays a role. For instance, individuals with seasonal pollen allergies might develop symptoms after eating certain raw fruits or vegetables due to shared protein structures, a condition known as pollen-food syndrome. Hormonal changes, such as during pregnancy or menopause, can influence immune responses and allergy development. Environmental factors like pollution, infections, or gut microbiome changes may contribute to increased immune sensitivity. Genetic predisposition can also influence whether someone develops allergies at any point in life.
Common Types of Adult-Onset Allergies
Adults can develop various types of allergies. Food allergies are common, with nearly half of adults reporting at least one that started in adulthood, even though many begin in childhood. Common adult-onset food allergens include shellfish, peanuts, tree nuts, and certain fruits or vegetables.
Environmental allergies include seasonal allergies (pollen from trees, grasses, ragweed) or year-round sensitivities (dust mites, mold spores, pet dander). Medication reactions can also develop, with antibiotics (penicillin) and NSAIDs being common culprits. Severe reactions to insect stings (bees, wasps) can also manifest unexpectedly. Latex allergies can arise in adulthood, particularly in individuals with increased exposure, like healthcare workers.
Recognizing and Managing Adult Allergies
Recognizing adult-onset allergy symptoms is key to seeking appropriate care. Symptoms vary by allergen and can include skin reactions (hives, rashes, swelling). Respiratory signs include sneezing, runny or stuffy nose, itchy and watery eyes, coughing, or wheezing. Some experience digestive issues like nausea, vomiting, abdominal pain, or diarrhea, especially with food allergies. A severe, life-threatening reaction known as anaphylaxis can occur suddenly, involving widespread symptoms like throat tightness, difficulty breathing, dizziness, or a sudden drop in blood pressure.
Consult a healthcare provider, such as a doctor or allergist, if new allergy symptoms affect daily life or if over-the-counter treatments are insufficient. They can conduct diagnostic tests to identify specific allergens. Common diagnostic methods include skin prick tests, where small amounts of allergens are applied to the skin to observe a reaction. Blood tests, specifically IgE antibody tests, measure the immune system’s response to allergens. In some cases, an oral food challenge, performed under medical supervision, may be used for food allergy diagnosis.
Managing adult-onset allergies often begins with allergen avoidance, a primary strategy to prevent reactions. When avoidance isn’t possible, various medications can alleviate symptoms. These include over-the-counter and prescription antihistamines (to block histamine release), nasal corticosteroids (to reduce inflammation), and decongestants for nasal congestion. Eye drops can also relieve itchy, watery eyes.
For those at risk of severe reactions, carrying an epinephrine auto-injector is recommended as a rapid response. Long-term management options for some allergies include immunotherapy, which involves receiving regular, small doses of an allergen through shots or sublingual tablets. This process helps the immune system build tolerance over time, potentially reducing the severity of allergic reactions.