Dairy Allergies and Mucus

A dairy allergy can cause increased mucus and congestion in your sinus cavity and in your lungs. Your sinuses are lined with mucus membranes that are easily irritated. When they’re irritated, they swell and begin to produce excessive amounts of mucus. If you’re allergic to dairy products, consuming dairy proteins can trigger inflammation and irritation in your sinuses, leading to greater mucus production. Avoid dairy products if you’ve been diagnosed with a milk allergy 1.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Dairy Allergy Mucus Cause

If you’re allergic to dairy products, your immune system has a hypersensitivity to the proteins found in milk, whey and casein. Although the proteins are safe for human consumption, your immune system mistakes them for dangerous substances. The body reacts by creating immunoglobulin E, or IgE antibodies, to fight off the proteins. The production of IgE antibodies causes mast cells to create histamine. Histamine is released in soft tissue throughout the body, which leads to inflammation, swelling and irritation. Increased histamine in the nasal passages triggers mucus production and congestion.

Mucus Symptoms

Inflammation and excessive mucus in the sinus cavity cause various symptoms. These may include stuffy nose, runny nose, sinus pressure, facial tenderness, sinus headaches and postnasal drip. Postnasal drip is a common condition that causes mucus to drip down the back of your throat because it cannot drain properly out of the nose. Mucus that drips down the back of the throat can lead to a sore throat, coughing and chest congestion.

Chest Congestion

Another part of the body that is directly impacted by a dairy allergy is your lungs. If histamine is released in your lungs, your airways become swollen, restricting your ability to breathe normally. You may feel mucus in your chest and become short of breath, begin wheezing or start coughing. Wheezing is a high-pitched sound made by your airways when they’re restricted. If you feel like you cannot breathe, become lightheaded or faint, call 911 for emergency medical attention.


The Food Allergy Research and Education website states that you should avoid consuming all dairy protein to effectively treat a milk allergy 12. The problem is, dairy protein isn't always listed as "milk" on food labels. Other names of milk you should look for include casein, custard, diacetyl, lactalbumin, lactalbumin phosphate, lactulose, rennet casein, whey protein hydrolysate and tagatose. Milk may be found in products you wouldn't suspect, such as caramels, luncheon meats and even products that are labeled "non-dairy." If you accidentally ingest dairy products, you may be able to treat minor symptoms such as excessive mucus, nasal congestion and chest congestion by taking an antihistamine and decongestant. Talk with your physician before taking any medication.