Allergies That Cause Runny Noses

Allergies, also called hypersensitivities, are excessive or abnormal responses to certain substances by the immune system that can result in a variety of physical symptoms. Common allergies include foods, environmental irritants inhaled through the nose and mouth, and contact allergies from clothing or outdoor exposures. Symptoms may include skin changes, headaches, nasal congestion and a runny nose. The Mayo Clinic and the American Academy of Allergy, Asthma and Immunology both offer information about allergies that cause runny noses.

Dander

• Regular exposure to pet dander may cause allergy symptoms, such as a runny nose. Dogs and cats that sleep on the family bed or sit on couches and chairs can leave hair and dead skin cells that trigger allergies. Dander from the skin of pets in the house can accumulate in the carpet and on other surfaces and cause a runny nose.

Foods

• Allergic reactions to foods may cause symptoms such as swelling, hives, congestion and a runny nose. Food allergies can develop at any time. Children may develop a runny nose from an allergy to foods such as milk or formula, soy, wheat or eggs. Adults may have allergies to foods such as peanuts and shellfish, which can cause a runny nose.

Insects

• Direct contact with certain insects, as well as exposure to body parts and waste of insects, may cause allergy symptoms such as a runny nose. People who are allergic to the venom from bee stings may develop a runny nose after being stung. Waste and body parts of cockroaches and dust mites can come into contact with the skin or become airborne and result in a runny nose.

Mold

• Molds are a type of fungi that can live both outside and inside houses and buildings. When molds reproduce, they make spores that float through the air and cause allergy symptoms such as a runny nose. The most common mold found inside of houses is Stachybotrys, which can grow on walls, wood and under carpets, and causes a runny nose both by allergic reactions and from poisons it releases into the air.

Pollen

• Allergies to pollen are also referred to as hay fever or allergic rhinitis, and are a common cause of runny noses in children and adults. Pollen allergies are usually seasonal and occur from spring through fall, until there is a freeze that stops pollen from being released. Pollen can get onto hair, clothes and pets while outside or can be inhaled directly into the nose, causing runny noses, congestion and facial swelling.

Plants

• Besides pollens produced by trees, grasses and weeds, coming into physical contact with certain types of plants may cause a runny nose. Allergies to plants such as poison ivy and oak may cause a runny nose, blisters and itching if the oils from the plant touch the nose or face. Smoke from burning vegetation may cause allergies that result in a runny nose.