You can develop an allergy at any point in life, even without prior allergic reactions. The immune system can undergo changes, leading to new sensitivities to previously tolerated substances. These new allergies can manifest in various ways, from mild discomfort to severe, life-threatening reactions.
Understanding How Allergies Develop
Allergies stem from an overactive immune response to typically harmless substances, known as allergens. The initial encounter with an allergen often leads to sensitization, which may not cause immediate symptoms. During sensitization, the immune system produces specific antibodies, primarily immunoglobulin E (IgE), which are tailored to recognize that particular allergen. These IgE antibodies then attach to specialized immune cells called mast cells, which are abundant in tissues such as the skin, lungs, and gastrointestinal tract.
Upon subsequent exposure to the same allergen, the allergen binds to the IgE antibodies on the surface of the mast cells. This binding triggers the mast cells to rapidly release various inflammatory chemicals, including histamine, into the surrounding tissues. Histamine causes many familiar allergy symptoms, such as itching, swelling, sneezing, nasal congestion, and airway constriction. This reaction can vary in speed depending on the individual and the allergen.
Common Allergens Appearing Later in Life
Many different substances can trigger new allergic reactions in adulthood, even those that were previously consumed or encountered without issue. Food allergies are common examples, with individuals sometimes developing sensitivities to foods like shellfish, peanuts, tree nuts, or fish later in life. These reactions can range from mild digestive upset or skin rashes to severe anaphylaxis.
Environmental allergens also frequently emerge in adulthood. People might suddenly become allergic to pollen from plants newly encountered in a different geographic region, or to pet dander from a new animal in the home. Drug allergies, such as those to certain antibiotics or pain relievers, can also appear unexpectedly. Insect sting allergies, like those to bee or wasp venom, may similarly develop after prior uneventful stings. These new sensitivities underscore the dynamic nature of the immune system throughout a person’s life.
Factors Influencing Adult Allergy Onset
Several factors can influence why an individual might suddenly develop allergies in adulthood. Changes in environmental exposure play a significant role; moving to a new region with different flora, acquiring a new pet, or starting a job with novel chemical exposures can introduce the immune system to unfamiliar allergens. Hormonal fluctuations are another contributing element. Events such as pregnancy, puberty, or menopause can alter the immune system’s balance, potentially leading to new allergic sensitivities.
Viral infections or other illnesses can sometimes temporarily or permanently modify the immune response, making the body more prone to developing allergies. Prolonged periods of stress may also impact immune function, with studies showing an increase in allergy symptoms in those experiencing chronic stress. Even the natural aging process can influence the immune system’s reactivity. Sometimes, an individual may have had a mild or unnoticed sensitization earlier in life that only manifests as a full-blown allergic reaction later due to increased exposure or other immunological shifts.
What to Do About New Allergic Symptoms
Recognizing the symptoms of a new allergy is the first step toward managing it. Allergic reactions can manifest in various ways, including skin rashes like hives, swelling of the face or lips, nasal congestion, sneezing, watery eyes, digestive issues such as nausea or stomach cramps, or even difficulty breathing. If you suspect you are experiencing new allergic symptoms, especially if they are severe or rapidly worsening, seeking medical attention is important.
A healthcare professional can help diagnose the specific allergen through various methods, including allergy skin prick tests or blood tests measuring IgE antibody levels. Once an allergy is identified, management typically involves avoiding the allergen as much as possible. Over-the-counter or prescription antihistamines can help alleviate milder symptoms. For severe reactions, especially those involving breathing difficulties or widespread symptoms, an epinephrine auto-injector may be prescribed for emergency use. Consulting with an allergist can provide a comprehensive plan for diagnosis and management.