What Causes Allergic Rhinitis?

Allergic rhinitis, commonly known as hay fever, is an inflammatory condition of the nasal passages caused by an allergic response to airborne allergens. When a person with allergic rhinitis comes into contact with these allergens, the immune system reacts by releasing chemicals such as histamine, leading to symptoms. Common allergens associated with allergic rhinitis include:

  • Pollen: Pollen from trees, grasses, and weeds is a common trigger, especially during specific seasons. Tree pollen is more prevalent in the spring, grass pollen in late spring and early summer, and weed pollen in late summer and fall.
  • Dust Mites: Tiny, microscopic insects found in house dust can trigger allergic rhinitis. Dust mites thrive in bedding, carpets, and upholstered furniture.
  • Mold Spores: Mold spores, which are more prevalent in damp or humid environments, can trigger allergic reactions. Indoor and outdoor molds can contribute to allergic rhinitis.
  • Pet Dander: Proteins found in the skin cells, urine, and saliva of animals can trigger allergic reactions in susceptible individuals. Pets such as cats, dogs, rabbits, and rodents are common sources.
  • Cockroach Droppings: Particles from cockroach droppings and saliva can act as allergens and trigger allergic rhinitis, particularly in urban environments.
  • Certain Foods: In some cases, certain foods can cross-react with pollen allergens, leading to a phenomenon known as oral allergy syndrome. For example, individuals allergic to birch pollen may experience symptoms when consuming certain fruits or vegetables.
  • Insect Venom: Stings or bites from insects such as bees, wasps, or hornets can trigger allergic reactions, including rhinitis, in some individuals.
  • Occupational Allergens: Certain workplace environments may expose individuals to allergens such as dust, chemicals, or animal proteins, contributing to occupational allergic rhinitis.
  • Air Pollution: While not a direct allergen, exposure to air pollution can exacerbate allergic rhinitis symptoms and contribute to overall respiratory irritation.
  • Tobacco Smoke: Exposure to tobacco smoke, either active smoking or passive exposure (secondhand smoke), can worsen allergic rhinitis symptoms.

Individuals with a family history of allergies or asthma may be more predisposed to developing allergic rhinitis. The condition can affect people of all ages, and the severity of symptoms can vary. Common symptoms of allergic rhinitis include sneezing, nasal congestion, runny nose, itching in the nose and eyes, and watery eyes.

Management of allergic rhinitis often involves avoiding allergens when possible, using antihistamines or nasal corticosteroids, and in severe cases, immunotherapy (allergy shots) may be considered. If someone suspects they have allergic rhinitis, consulting with an allergist or healthcare professional for proper diagnosis and management is recommended.