A common symptom of a food allergy is nasal congestion. Nasal congestion is the result of inflammation in the sinus cavity that leads to swollen and irritated sinuses, according to the University of Maryland. Nasal congestion from food allergies is treatable, but a food allergy is not curable. If someone suspects she has a food allergy, she should see an allergist to undergo allergy tests. Nasal congestion from food allergies can lead to sinus pain, postnasal drip and a stuffy nose.
A milk allergy is a hypersensitivity of the immune system to the proteins found in cow's milk. Cow's milk can cause increased nasal congestion because of the allergic reaction and cow's milk ability to produce mucus. Someone with a milk allergy will experience other symptoms, other than nasal congestion, such as stomach pain, diarrhea and hives. Milk is divided into two parts -- the whey and the curd, according to KidsHealth.org. Whey is the liquid part of milk, while curd is the part of milk used to make cheese. Most people are allergic to the proteins in one part or the other of milk. Even if someone is exclusively allergic to whey, it is advisable to avoid all dairy products because of the risk of cross-contamination.
A tree nut allergy is a common food allergy. Unlike other food allergies, a tree nut allergy is only outgrown by around nine percent of children, according to the Food Allergy Initiative. Most other food allergies are outgrown by the age of five. Tree nuts tend to be highly allergic and can lead to anaphylactic shock. Nasal congestion is one of the first signs of anaphylaxis and will be accompanied by a faint pulse, a rapid heartbeat and lightheadedness. A tree nut allergy may also cause hives, the lips to swell and the inability to breath. Talk with a doctor if these symptoms persist. The FDA requires that all pre-packaged food disclose the use of tree nuts or the possibility of the food being contaminated by nut byproducts.
A wheat allergy causes nasal congestion. An allergy to wheat is commonly confused with wheat intolerance. Wheat intolerance is a lack of proper enzymes to properly digest wheat. The most common wheat allergy is to the gluten protein. MayoClinic.com recommends that someone with a wheat allergy inform others of her condition and should wear a medical bracelet, in case of emergency.