Food allergy is a kind of immune system reaction that is happening very soon after you have some food. Even you have eaten a small piece of allergy – causing foods can trigger the symptoms and signs of this condition such as swollen airways, hives or digestive problems. Also there are some cases when food is causing severe symptoms of allergy or in some cases this is a life – threatening condition which is known as anaphylaxis. 3% of adults are affected with food allergy and 6% – 8% of children under age of 3 are affected with food allergy [1,2]. There is no cure for this condition. Some children outgrow this condition as they get older. Many people are confusing food allergy with other condition which is known as food intolerance. If you have this condition, then it can bother you in your everyday activities. But the food intolerance is a less serious condition and this condition does not involve your immune system.
Symptoms of food allergy
There are some people who are allergic to food. This is not severe condition but it is a very uncomfortable. But also there are some people who are allergic to food and this is a very frightening condition and in many cases it is life – threatening condition. The symptoms of this condition usually develop from few minutes to two hours after they have eaten this food. Here are the most common signs and symptoms of food allergy:
- Dizziness, lightheadedness or fainting
- Abdominal pain, diarrhea, nausea or vomiting
- Wheezing, nasal congestion or trouble breathing
- Swelling of the lips, face, tongue and throat or other parts of the body
- Hives, itching or eczema
- Tingling or itching in the mouth
Anaphylaxis: There are some people who can get severe allergic reaction which is known as anaphylaxis. This is a life – threatening condition which has some signs and symptoms such as 
- Dizziness, lightheadedness or loss of consciousness
- Rapid pulse
- Shock with a severe drop in blood pressure
- A swollen throat or the sensation of a lump in your throat that makes it difficult to breathe
- Constriction and tightening of airways.
If you let this condition untreated, then it can cause coma or death.
Causes: When people suffer from food allergy, then their immune systems are making mistakes because they identify some food or substance like something harmful for our bodies. Your immune system triggers your body to release immunoglobulin which is antibodies. They are released to neutralize the allergen (food substance) or the culprit food. The next time you eat this food (even you eat the smallest part of this food), then the lgE antibodies are sensing this food. Then, they produce a signal to your immune system to release histamine which is a chemical. Also they stimulate your immune system to produce other types of chemicals in your bloodstream. These chemicals can cause you many different signs and symptoms in your body. They are a reason why your body has allergic responses such as labored breathing, diarrhea, nausea, hives, rashes, dry throat, itchy nose, dripping nose and in some cases is a reason for anaphylactic shock.
The majority of food allergy are triggered by certain proteins in:
- Tree nuts such as pecans and walnuts
- Shellfish such as crab, lobster and shrimp
In children, food allergies are commonly triggered by proteins in:
- Tree nuts
Risk factors: There are some factors which can increase the risk of getting food allergy such as
- Age: Toddlers and infants are having the biggest chances to get food allergy. As we are growing older our digestive system matures and our body is not absorbing some food components that can trigger allergies. Children outgrow allergies to eggs, wheat, soy and milk. But in the most cases if they are allergic to shellfish and nuts, then these can be life threatening conditions. 
- Family history: If allergies such as high fever, eczema and asthma are common in your family, then you have increased chances to get food allergy. 
- Asthma: Food allergy and asthma in most cases are occurring together; in this case the signs and symptoms are more severe. 
 Wang J. Management of the patient with multiple food allergies. Current Allergy and Asthma Reports. 2010;10(4):271-7.
 Allergy UK. Allergy prevalence: Useful facts and figures. Retrieved from allergyuk.org/assets/000/001/369/Stats_for_Website_original.pdf
 Daya MA, Du Toit G. Anaphylaxis: symptoms, causes and diagnosis. The Pharmaceutical Journal. 2020. Retrieved from pharmaceutical-journal.com/article/ld/anaphylaxis-symptoms-causes-and-diagnosis
 Chin B, Chan ES, Goldman RD. Early exposure to food and food allergy in children. Canadian Family Physician. 2014;60(4):338-9.
 Koplin JJ, Allen KJ, Gurrin LC, et al. The impact of family history of allergy on risk of food allergy: A population-based study of infants. International Journal of Environmental Research and Public Health. 2013;10(11):5364–77.
 Emons JAM, van Wijk RG. Food allergy and asthma: Is there a link? Current Treatment Options in Allergy. 2018;5(4):436–44.