What is a Food Allergy? Types, Symptoms, Treatment
Food allergies develop when the immune system reacts inappropriately to food proteins. They can cause a wide range of symptoms, from abdominal pain and cramping, to headaches, hives, inflammation, and anaphylaxis. Onset of symptoms can be immediate, but may take several hours, depending on the severity of the allergy. The most common allergy-causing foods are nuts, shellfish, fish, wheat, eggs, cow’s milk or lactose, and soy.
What Causes Food Allergies?
Food allergies are caused by inappropriate immune system reactions to food proteins, but why do these reactions occur? The immune system generates infection-fighting cells that are highly specific, and in a healthy immune system any cells that react to food proteins are destroyed or never become activated. In someone with a food allergy, some immune cells become primed to react strongly to certain food proteins. The symptoms of a food allergy are essentially the symptoms of a very strong and highly specific immune response, in which the responding immune cells release histamines and other chemicals that cause inflammation in the affected area.
The allergic response has two phases, and one or both may occur during an allergic attack. In an acute phase reaction, the symptoms appear immediately on contact with the allergy-inducing food, and can include facial itching and swelling, and throat swelling. In severe cases the swelling may cause the airway to close. Late-phase symptoms typically develop between two and four hours after the exposure to the allergic food, and involve digestive problems such as vomiting and diarrhea, gas, bloating, and abdominal pain.
Risk Factors for Allergy Development
While the allergic response itself has been well-documented, the reason why the immune system becomes sensitized to response to food proteins is not clear. What is clear is that rather than there being one single factor that causes people to develop allergies, there are instead a number of risk factors that increase the likelihood that a given individual will become allergic to one or more substances.
The strongest factor is simply genetic inheritance: parents with allergies are more likely to have children who develop allergies, and 70% of pairs of identical twins have the same allergies. Genetic predisposition is only a risk factor, however; while the tendency to develop allergies does run in families, genetic inheritance isn’t the only influence.
Preventing and Treating Symptoms of Food Allergy
The most effective way to prevent symptoms of food allergy is simply to avoid the foods that cause symptoms. However, for someone with an allergy, it’s always a good idea to be prepared with medication on hand in case allergy-inducing food is accidentally eaten.
Depending on the severity of the allergy, medication ranges from antihistamines and other anti-inflammatory medications, to immune system-suppressing glucocorticoids, to epinephrine injections. Epinephrine, also known as adrenaline, is typically prescribed for people with severe and potentially life-threatening allergies with immediate-onset symptoms, and is administered as an injection to limit the massive and rapid swelling that occurs.
While all of these medications effectively treat the symptoms of food allergies, they’re not able to cure the condition. However, while some children do grow out of food allergies, any allergies a person has as an adult are typically there for life. It should be noted that while most allergy medications are not subject to abuse, some over-the-counter allergy medications can cause dangerous side effects when taken with alcohol, benzodiazepines, and certain types of painkillers.
Reports on Georgia’s drug use, and that of many other states, indicates that allergy medications containing pseudoephedrine are also subject to abuse, largely because they are used in the production of methamphetamine. All allergy medications should therefore be kept close at hand, not only out of necessity, but also to prevent abuse.
Can Allergies be prevented?
If you have one or more allergies, there are plenty of options for preventing the symptoms, but there is currently no way to prevent allergies from developing in the first place. In fact, there is evidence that allergies are more common in children than they were even a decade ago—in the US, for example, around 6% of children have food allergies, and around 12% have asthma.
There are many theories as to why increasing numbers of children are developing allergies. For example, factors such as reduced sun exposure, reduced physical activity, increased exposure to chemicals, and overuse of antibiotics, might play a role, because all of these things are known to weaken and disrupt the immune system.
The most popular theory about the increase in allergies among children in developed countries is that because children are in general healthier and affected by fewer types of infections, their immune systems may be less adept at making the distinction between harmful and benign proteins. They are therefore more likely to react inappropriately to harmless substances such as food and pollen.
Anoop Nain is a content marketer and health blogger who is currently working with rehabtip.com. He has covered the topics related to health, fitness, and lifestyle. He specializes in condensing complex health information into easy articles that are understandable to the readers of his niche.