Overview
Allergies occur when the immune system reacts to substances that are usually harmless, called allergens. The reaction can range from mild irritation to severe, life-threatening responses.
Symptoms
Sneezing or runny nose Itchy or watery eyes Skin rashes, hives, or eczema Swelling of lips, tongue, or face Coughing, wheezing, or difficulty breathing Stomach pain, nausea, or vomiting (food allergies) Anaphylaxis – severe, rapid allergic reaction (rare but serious)
Causes
Allergic reactions are triggered by allergens. Common allergens include:
Pollen from trees, grass, and weeds Dust mites Animal dander Insect stings (bees, wasps) Foods such as peanuts, shellfish, milk, eggs, and soy Medications like penicillin or other antibiotics Mold spores
Diagnosis
Detailed medical history and symptom review Physical examination Skin prick testing to identify specific allergens Blood tests to measure allergen-specific antibodies Elimination diets for suspected food allergies
Treatment
Avoidance of known allergens Antihistamines to relieve mild symptoms Nasal corticosteroids for nasal allergies Topical creams for skin reactions Epinephrine injection for severe anaphylactic reactions Allergen immunotherapy (allergy shots or tablets) for long-term control
Complications
Sinus infections Asthma attacks or worsening of asthma Severe allergic reactions leading to anaphylaxis Chronic skin conditions from repeated exposure
Prevention
Identify and avoid triggers whenever possible Use air filters and clean home environments to reduce allergens Read food labels carefully Wear medical alert identification if at risk for severe reactions Follow prescribed medications during allergy seasons