The most common allergens that cause Respiratory Tract Infections are:

Airborne allergens

Contact with proteins found in certain airborne particles may trigger Allergic Rhinitis. These allergic proteins can come from a variety of sources:

Community-wide:

• Pollen (Small, powdery grains of flowering plants that can easily become airborne)
• Trees
• Grass
• Weeds
• Moulds: Alternaria, Cladosporium (Tiny fungus spores that can become airborne, usually found in damp areas, basements and bathrooms)
• Insects

Household allergens

• Dust mites (Microscopic insects that inhabit household dust and are found indoors, in areas where air circulation is poor and on surfaces like carpets, bedding and stuffed animals)
• Cockroaches (Droppings, eggs, saliva and small pieces of the outer shell of cockroaches)
• Pets (Tiny scales or particles from the skin of a pet, usually shed by dogs and cats)
• Moulds and bacteria in fans, humidifiers and air conditioners
• Mildew

Occupational allergens

Your work environment may expose you to substances, chemicals and conditions that may make you uncomfortable. Some of these may be related to:

• Agricultural and food-processing: grain dust (storage mites), hay dust, soy, castor, coffee beans, sunflower seed, cottonseed, flaxseed, wheat flour, rye flour, shell fish, fish, woodworks
• Chemical industry: Plastics (eg, diisocyanates, trimelitic anhydride), metals (eg. nickel, platinum), pharmaceuticals, detergents (Bacillus subtilis enzymes)
• Textile industry: Byssinosis (cotton bract dust)
• Cosmetic products: Perfumes, hair dyes, bleaches, cologne, soap, candles, skin lotions, sunscreens, deodorants, lipsticks. Even products containing natural plant extracts can cause mild allergic reactions. Others may result in severe reactions like shortness of breath, cold-like symptoms or worsening asthma symptoms.
• Laboratory animals : rodent urine