Can Food Allergies Cause Coughing?

It is usual for people to have a cough due to  seasonal allergies such as flu or a cold that may last for a few days and then taper off. However, many people do experience infrequent or chronic coughs after having a meal. Among several possible triggers, food allergies are one of the most frequent causes of coughing. 

Food-related allergies and other types of food hypersensitivity are common and affect millions of people around the globe. This generally happens when our defensive mechanism, called the immune system, reacts to specific kinds of food in an unusual manner. This may occur within a few hours of eating a meal. Even a negligible amount of food can trigger allergic symptoms such as digestive problems, rashes, coughs, and breathing issues. Although the majority of food allergy symptoms are mild or uncomfortable,  in some people, food allergies may trigger potential life-threatening health problems such as anaphylaxis.

There are three major known types of food allergies to understand why food substances can trigger a reaction:

• IgE-mediated food allergy (most common): During an allergic reaction, the immune system produces a special type of antibody called Immunoglobulin E, or IgE. The IgE antibody mistakenly targets harmless food proteins as a threat, alerting the immune cells to release various chemicals such as histamines when exposed to food allergens 
• Non-IgE-mediated food allergies: These types of allergic reactions are mediated by different types of immune cells rather than IgE antibodies. The non-IgE-mediated food allergy is difficult to pinpoint as there are no accurate tests to affirm its diagnosis and the symptoms develop after several hours 
• Mixed IgE and non-IgE-mediated food allergies: Individuals may experience a combination of symptoms from both types

Food that can trigger allergies

According to the Association of UK dietitians, it is estimated that around 1–10% of children and adults experience food hypersensitivity.

It is still not known why people develop food allergies. However, they often have other allergies such as eczema, hay fever, and asthma. Most infants experience food allergies along with eczema or hives.

Food-causing allergic reactions can be frightening. Such reactions may trigger respiratory symptoms such as:

• Nasal congestion
• Runny nose
• Wheezing
• Persistent cough
• Itchy throat 
• Nausea

Food allergies are sometimes also confused with food intolerances, which is a different condition primarily related to digestive issues in comparison to food allergies that involve the immune system.

Any food can lead to an allergic reaction. However, there are certain foods that have been identified as  prevalent food allergens:

• Eggs: These are the most common cause of egg allergy among adults and younger children. People tend to have allergies to all foods that contain eggs. However, most children outgrow their egg allergy before adolescence
• Wheat: Wheat allergies usually happen when wheat proteins prime the immune system for an allergic response. Individuals may develop an allergy to any of the four recognised classes of wheat called albumin, globulin, gluten, or gliadin. Wheat allergies are sometimes mistaken for celiac disease, but both these conditions are different 
• Milk: also known as the common cause of cow milk (protein) allergy or CMA/CMPA, which generally occurs in response to the milk proteins whey and casein. Milk allergies are mostly found in infants and young children. However, sometimes it persists into adulthood as well
• Peanuts: Peanut allergies are considered long-lasting conditions. Individuals, particularly children, rarely outgrow peanut hypersensitivity. For this very reason, peanut allergies can have a serious impact on health and accidental exposure may require immediate medical attention 
• Fish: Unlike other food allergies, fish allergies become more apparent in adults in comparison to young children. A study reported that nearly 40% of people did not experience fish allergies until they reached adulthood¹
• Sulphites: are generally used as a preservative for food and beverages. If someone is sensitive to sulphites or sulphur dioxide-containing substances, then they may have trouble breathing and coughing as an allergic reaction. This happens when sulphite interacts with stomach acid. The acid influx can disperse back into the respiratory airway, resulting in airway obstruction and irritation. Sulphites sensitivity can affect 13% of asthma people
• Fruits and vegetables: Some people experience hypersensitivity when they eat certain fruits, vegetables, or nuts in their raw or fresh form. This type of allergy is typically referred to as oral allergy syndrome or pollen allergy syndrome. This is commonly observed in people who have hay fever (allergic rhinitis)

Other common food allergens may include:

• Shellfish (prawns, lobsters, or crabs) 
• Meat - due to the presence of a carbohydrate referred to as alpha-galactose (alpha-gal) 
• Soybeans
• Tree nuts
• Pine-nuts
• Gluten-containing cereals such as oats or barley 
• Celery
• Sesame seeds
• Mustard seeds

Prevention

Enduring food allergies can be a daunting experience. To prevent such  incidents, it is advised to avoid and identify foods that can trigger an allergy. Taking precautions may also assist in managing the signs and symptoms. 

• It is best to read labels on packages prior to purchasing any food product 
• Wear a medical ID wristband containing all the relevant information about your food allergy 
• Dine out carefully. Let your server or chef know specifics about your food allergies before ordering a meal 
• Plan your meals accordingly at home 
• Carry your prescribed medications for emergency situations

There’s no known cure for food allergies. Many health researchers are looking into ways to desensitise food allergens, although further research is still required for effective strategies to prevent food allergies at the community level. 

According to one study, breastfeeding may provide excellent sources of nutrients, growth factors, and maternal protective antibodies for infants, serving as an early dietary introduction to food allergens.²

Supplementations of prebiotics and probiotics have also been proposed for preventing allergic reactions due to their anti-inflammatory effects, although it is debatable.³ 

Some scientists believe that germ-free environments have  greatly contributed to the rise of food allergies (hygiene hypothesis). Early exposure to environmental germs plays a vital role in developing children's immune systems and promotes healthy gut microbes.²

It  found that early exposure to food products in high-risk individuals has a reduced chance of developing allergies in later life.

Medicine to take or home remedies

Food allergy symptoms vary from person to person. Depending on the severity, doctors may prescribe certain medications to counter allergic reactions. This may include:

• Antihistamines - used to alleviate itching and congestion caused by mild to severe allergies 
• Epinephrine - helps to counteract low blood pressure and ease breathing problems. It is usually considered an effective treatment option for severe symptoms (anaphylaxis) that can be administered through an auto-injector pen (EpiPen, Jext)
• In the case of food allergy rashes, it is advised to wash the suspected surfaces and apply over-the-counter creams (hydrocortisone) to ease itching or redness

When to see a doctor?

If you believe you or your child may have developed a food allergy,  it is best to talk with a medical professional or allergist for a diagnosis and to plan precautionary strategies. Moreover, it is advised to seek immediate medical attention if any sign of anaphylaxis is observed, such as:

• Troubled breathing with a persistent cough 
• Rapid heartbeat
• Chest pain
• Shock with an extensive fall in blood pressure 
• Dizziness
• Flushed or pale skin
• Loss of consciousness

Summary

A food allergy is an abnormal immune system reaction to certain food substances after having a meal. Food allergies typically cause mild or unpleasant symptoms, but sometimes they may pose a potential life threat, which  requires immediate medical attention. There is no cure for the condition, but it is  manageable. It is recommended to follow the  guidelines and medications advised by medical professionals. Identifying trigger foods can primarily help to prevent future episodes of allergic reactions.