Millions of people across the world struggle with allergies. Many allergies are due to food, causing an allergic reaction. Histamine is released in the body after eating these foods, causing the reaction and inflammation. Symptoms can occur quickly or hours later and include swelling around the face, difficulty breathing, low blood pressure, nausea and vomiting, diarrhea and hives or other itchy rashes.

Below you will find five common allergic triggers that are food based:

1. Milk (casein) allergy

Milk and dairy products are of the most common allergic triggers. Most of the time this allergy disappears before adulthood and mainly affects children. It is a more difficult allergy to diagnose as symptoms often resemble lactose intolerance. Inflammation from this trigger usually occurs in the gastrointestinal tract. Common symptoms include vomiting, pain, diarrhea and constipation. If you have this allergy, it is imperative to try to avoid dairy and dairy related products.

2. Shellfish allergy

This food allergic trigger is caused by your body attacking the proteins present in shellfish. Most of the time, tropomyosin is the protein that is to blame though the body can attack arginine kinase and myosin light chain as well. This allergy is also difficult to diagnose as it can seem like an adverse reaction to the food. Symptoms of this allergy come on rather quickly. Most symptoms of this allergy are gastrointestinal in nature including constipation, nausea and vomiting and diarrhea. Most people do not outgrow this allergy, even sometimes having the smell of shellfish trigger the allergic response.

3. Egg allergy

This food trigger is the second most common after milk casein among children. Most children will outgrow this allergy into adulthood as well. Some individuals are just triggered by egg whites or egg yolks rather than the whole egg, with an egg white allergy being more common. Heating eggs can change the chemical buildup, allowing heated eggs to not cause a reaction. Eggs do have a more severe reaction, however. Symptoms may include gastrointestinal symptoms and stomach pain, hives and rashes, breathing difficulties and rarely, anaphylaxis.

4. Wheat allergy (celiac disease)

Wheat based allergic reactions are triggered by the proteins in wheat. Wheat allergy is common among children. Wheat intolerance based celiac disease is more common among adults and has differing symptoms. Celiac disease is not life threatening and is a reaction to gluten that is in wheat. Celiac disease symptoms include gastrointestinal symptoms and stomach pain. True wheat allergy symptoms can be more life threatening. The symptoms include gastrointestinal pain, hives and rashes, nausea and vomiting, swelling and rarely, anaphylaxis.

5. Nut allergy

There are varying types of nut allergies including tree nut allergies and peanut allergies. Tree nut allergies are very common among people of all ages. It is important to avoid all types so as not to develop more allergies. Symptoms are very severe with fifty percent of allergy related deaths attributed to tree nuts so it is essential to have an epi pen. Symptoms include anaphylaxis and breathing difficulties. A peanut allergy is another type of allergy that is very common among people of all ages. This allergy also requires ownership of an epi pen due to its severe reactions. Symptoms include anaphylaxis and breathing difficulties as well.