The Physiology of Allergies

The Physiology of Allergies

Allergies are a common health condition affecting about 50 million individuals in the United States each year. The condition occurs in individuals of all ages.

Multiple types of allergies occur secondary to many different allergens, and individuals can have mild or severe symptoms or no symptoms. Several treatment and management protocols can be utilized for allergic conditions.

In what follows, we’ll be exploring the physiology of allergies and will define how they develop. We’ll also discuss the role that antibodies play and how particular treatment works to counteract the physiology of allergic reactions.



An allergy is defined as an immune system reaction to a foreign intruder, such as pollen, fur, venom, mold, or food that doesn’t agree with your biology. This means that the foreign substance causes the body’s immune system to react and produce antibodies against the substance. The substance might not even be harmful, and it can still trigger the immune system to react. If this occurs, the substance is an allergen to the individual.

Through the stimulation of immune cells that then release chemicals to signal an unwelcomed intruder, allergenic substances ultimately cause a ripple effect of potential symptoms, ranging in severity from mild to severe and can be fatal.

Mild allergic signs and symptoms may include generalized itchiness, rashes, or congestion. Moderate allergic signs and symptoms may include intensified itch, shortness of breath, moderate swelling, or wheezing when breathing. Severe allergic signs and symptoms may include vomiting, confusion, low blood pressure, swelling of the airway that can lead to difficulty swallowing and life-threatening respiratory distress.

There are several types of allergies, including drug allergies, food allergies, pet allergies, pollen allergies, and insect allergies. Each of these substances can lead to symptoms that can be mild or severe, depending on the individual.

Causes of Allergies

Although the study of allergies and immunology has not conclusively identified why certain allergies occur, there is a level of certainty that there is a genetic component. In addition, though the development of allergic issues in a child of someone with specific allergies is not absolutely predictable, a higher likelihood of the allergic condition exists in these children. They may also be more likely than nonallergic individuals to develop allergies in their later years.

Autoimmune conditions in which the body develops antibodies against itself, such as Lupus or Rheumatoid Arthritis, may have a correlation with general allergic illness. Studies have also suggested that individuals who have allergic conditions have a higher risk of developing autoimmune conditions than the general population.

Though allergic reactions range in type, those that present a noticeable physical reaction, such as hives, which are the red welts on the skin, are the result of histamine release. During such a reaction, histamine is released from mast cells (a type of white blood cell) and causes symptoms such as hives and swelling.

The body’s response to a substance that it identifies as an allergen can be dramatic and rapid with the development of IgE antibodies. IgE antibodies are the type of antibodies produced by the immune system in response to an allergen. The body also has other blood cells that help defend against disease, infection, and allergens which are known as eosinophils.

Allergic reaction treatment and management options are readily available for any type of allergy, and the treatment is often timely and effective. These interventions can often be done without requiring an immediate visit to your medical provider in each incident.

Allergy Treatment and Management

The treatment and management options for allergic reactions often fall into the categories of oral medications, injectable medications, and immunotherapy. Some natural therapies can also be helpful as alternatives.

The following are the most common management options for different allergies:

Oral Medications

Depending on the allergy, oral medications are often utilized. Different medications can be utilized for the treatment of most mild allergies, such as antihistamines, corticosteroids, and decongestants. These medications can be useful as an allergy symptom reliever after the onset of symptoms or as a preventative medication.

Injectable Medication

Epinephrine is a hormone and a neurotransmitter that causes vasoconstriction of the smooth muscle of blood vessels, Injectable medications are most often used in emergent situations, and an example of this type of medication is epinephrine. Epinephrine is a hormone and a neurotransmitter that causes vasoconstriction of the smooth muscle of blood vessels, and it also causes relaxation of the smooth muscle of the bronchial tubes in the lungs. These qualities help to counteract the complications that occur in a severe allergic reaction. Epinephrine can be administered through what’s most commonly known as an EpiPen.


Immunotherapy is a different treatment option that is utilized as a preventative measure for allergy management. In the process, an allergen substance is injected in a very small amount to induce a small allergic reaction.

Through the use of this method, the body is trained to handle small amounts of the particular allergen, and over time, the body adapts and will have a progressively improved response to the allergen.

Natural Remedies

While most natural remedies are only effective for the mildest of cases, the majority of them are easily implemented. Examples of natural remedies include herbal teas and certain essential oils.

Final Thoughts

Allergies can range from mild to very severe, and they can range from simply annoying symptoms to life-threatening emergencies.

Most allergies, however, are both treatable and manageable and, in some cases, can be prevented.

Food Allergies Part 1

Food Allergies Part 1

Food allergies are becoming increasingly common among children and adults alike. It seems as though everyone knows someone who suffers from a food allergy. The most typical food allergies include dairy, soy, nuts, shellfish, and others.

Some additional types of food allergies include seed, gluten, and wheat allergies.

While the majority of food allergies occur during childhood, they often persist throughout adulthood. With an increase in awareness surrounding food allergies, it is important to understand the signs and symptoms of a food allergy and how to avoid them where possible.

In what follows, we’ll discuss the different signs and symptoms associated with food allergies, detailing the three main categories of food allergies and their characteristics. In part two of this topic, we’ll explore several ways to prevent such allergies, focusing primarily on childhood allergies and how breastfeeding may be a potential solution.

Common Signs and Symptoms of Food Allergies

Food allergies are becoming increasingly common among children and adults alike. It seems as though everyone knows someone who suffers from a food allergy. The most typical food allergies include dairy, soy, nuts, shellfish, and others.

Flat lay composition of different products and wooden cubes with words Food Allergy on white marble table

Signs and symptoms will vary depending on the category, type, and severity of food allergy. There are, however, several common signs and symptoms that tend to be associated with food allergies.

No matter the category, type, or severity, the signs and symptoms of food allergies often present themselves almost immediately after ingestion of the food allergen itself. This, unlike other types of allergies, is a significant distinction of food allergies. This quality can significantly assist a clinician in making the diagnosis of some specific types of food allergy.

Although immediate symptoms are the most common presentation, in other particular types of food allergies, this doesn’t always occur. As will be discussed, non-IgE-mediated allergies can take days for any signs or symptoms to become evident.

The following are the most common signs and symptoms of the most prevalent food allergies, present in both children and adults alike:

  • Itchiness of the Skin, Eyes, or Mouth
  • Hives
  • Skin Redness
  • Swelling of the Face or Mouth
  • Shortness of Breath
  • Lightheadedness
  • Nausea and Vomiting
  • Abdominal Pain

In the most severe of circumstances, anaphylaxis can occur, characterized by a state of shock that can be life-threatening unless immediate emergent attention is received and medication administered, such as epinephrine or otherwise.

Severe food allergies can produce alarming and often dangerous reactions such as severe hives.

Woman scratching her neck, isolated on white

Three Categories of Food Allergies

The discussion of categories of food allergies refers to the subtypes under the main types of food allergies. The categories are distinguished by the causes, length of time of the allergy, and specific symptoms.

The three (3) main categories of food allergies are:

  • IgE-Mediated (Cat. 1)
  • Non-IgE-Mediated (Cat. 2)
  • Mixed Category (Both IgE and Non-IgE)

IgE-Mediated (Cat. 1)

Category 1 food allergies are caused by an immune system response that produces antibodies against specific proteins found in specific foods. These antibodies attack the proteins in the food and cause a cascade of responses that cause inflammation in the body and result in symptoms such as hives, eczema, asthma attacks, vomiting, diarrhea, abdominal pain, fatigue, headaches, and joint pain.

This first category of food allergy usually presents itself in individuals between 6 months and 5 years of age. The most common foods involved in IgE-Mediated food allergies include cow’s milk, egg whites, peanuts, tree nuts, wheat, soy, and corn.

Non-IgE-Mediated (Cat. 2)

Unlike IgE-Mediated food allergies, category 2 food allergies involve a reaction that doesn’t involve the presence of antibodies.

Non-IgE-Mediated food allergies are typically associated with delayed hypersensitivity responses. Such responses can include contact dermatitis, urticaria, angioedema, rhino-conjunctivitis, oral allergic syndrome, eosinophilic gastroenteritis, atopic keratoconjunctivitis, and anaphylaxis.

Symptoms involved in Cat. 2 food allergies typically appear within minutes to just a few hours after eating the particular food. The most common foods involved with category 2 food allergies include fruits, vegetables, legumes, spices, chocolate, citrus fruit, tomatoes, garlic, onions, strawberries, celery, nuts, shellfish, and alcohol.

White blood cell B lymphocyte plasma cell producing antibodies isolated on white backgroundMixed (IgE and Non-IgE)

Food allergies that involve a combination of mediators are known as IgE-Mediated and Non-IgE-Mediated responses. An individual who develops a food allergy that has aspects that are mediated by antibodies and aspects that are not caused by antibodies is in this category.

Whichever category or type in question, it’s approximated that 10% of the world’s population lives with some form of food allergy. If this population of individuals is limited to the United States, it’s estimated that 5% of children and 4% of adults live with one or more food allergies. Of these, 20% are said to be severe allergies.

According to the National Institute of Health, 30,000 fatalities occur yearly due to food-borne allergies.

Final Thoughts

During the suspicion of any type or category of food allergy, whether mild or severe, it’s important to avoid exposure to the suspected food until a proper diagnosis has been made by a medical professional.

Should a mild reaction occur before reaching a doctor, antihistamines are the first recommended treatment. However, emergent medical attention is required when a more severe reaction occurs.


Food Allergies Part 2

Food Allergies Part 2

Concept of food allergies. Set of products that cause allergies: citrus, red fruits and berries, eggs, milk, white bread, nuts, chocolate, coffee, honeyAbout 50 million people in the United States annually suffer from the effects and symptoms of allergies. Of those 50 million, 10% or more are food allergies (6% of children and 4% of adults).

Ranging in category, type, and severity, food allergies are among the most common type of allergy, prevalent in both children and adults. Food allergies can also develop over time, meaning that individuals will later develop an allergy that never previously impacted their health.

Because of the prevalence and potentially life-threatening consequences of food allergies, it’s important to review and implement the most effective and research-backed preventative measures.

In what follows, we’ll be exploring some of the possible ways to prevent food-borne allergies, particularly in children, but also relevant to adults.

Prevention of Food Allergies

In order to prevent food allergies, it’s important to consider research on the subject. While some of the following proposed preventative strategies can transfer to both children and adults, the initial focus will be placed on the development of childhood allergies.

The following are 4 possible preventative mechanisms regarding the development of food allergies, particularly during childhood.

Breastfeeding offers an array of benefits to babies. It may possibly reduce incidences of food allergies -- more research nedds to be done on it.  Young mother breastfeeding  her newborn baby boy at home.

Breastfeeding and Food Allergies

The first thing to consider when seeking possible ways to protect an infant from the risk of food allergies is whether or not the child is breastfed or formula fed. While both have their pros and cons as it relates to the general health and development of the child, it has become a popular opinion that breastfeeding may be helpful in reducing the risk of developing food allergies.

Breastmilk has been shown to have protective immune qualities. For example, breastmilk immunoglobulins help protect babies from infection, illness, and long-term disease. Infants who are breastfed are less susceptible to respiratory tract infections, ear infections, urinary tract infections, as well as diabetes, asthma, and general stomach viruses. In addition, breastfeeding reduces the risk of gastrointestinal infections such as rotavirus and giardia lamblia.

Although the benefits of breastfeeding are clear, studies have not definitively demonstrated a causal relationship between breastfeeding and decreased incidence of food allergies in children. While the benefits of breastmilk are widespread and promising, more research on the benefits of breastfeeding as a preventative mechanism for food allergy development needs to be done to determine a conclusive relationship.

Avoid Common Food Allergens Altogether

If bottle-feeding is the method of choice during the initial months of an infant’s life, it’s important to remain consistent with this method, at least for the first four months, but ideally for six months or more. Studies have suggested that introducing solid food before six months of age increases the risk of developing food sensitivities and potential allergies later in life.

Some of the most common solid foods that can potentially cause immune responses are certain meats, cheeses, sauces, gravies, salad dressings, pickles, olives, packaged goods such as cookies and chips, and even raw meats such as liver and kidney. With this knowledge, parents can decide if they wish to avoid these foods or introduce them with caution.

Ensure Proper Nutrition

It’s also important to consider proper nutrition as a means of prevention of food allergies, not to mention the promotion of general health and longevity.

Ensuring that a child’s diet consists of plenty of fruits, vegetables, and other whole foods rich in vitamins and minerals like vitamins D and C will help the prevention of food allergy development. Vitamin D helps to decrease the immune response and can help decrease the likelihood of the development of an immune reaction to foods.

Research shows that infants who receive adequate amounts of vitamin D early in life have a reduced risk of developing food allergies later in life. Vitamin D also plays a role in maintaining healthy gut flora and preventing intestinal infections.

Limit Caffeine Consumption

Finally, consider limiting caffeine consumption, especially when pregnant or breastfeeding. Caffeine has been shown to affect the central nervous system, thus leading to the development of complications such as anxiety, insomnia, and irritability.

As it relates to allergies, caffeine contains naturally high levels of histamines, which is a strong mediator in the immune response. Higher levels could be correlated with higher response activity.


Consider limiting caffeine consumption, especially when pregnant or breastfeeding. Caffeine has been shown to affect the central nervous system, thus leading to the development of complications such as anxiety, insomnia, and irritability.

In one study, it was suggested that caffeine intake during pregnancy may have an influence on a child’s development of food allergies later in life.

If you suspect that your child is suffering from a food allergy, consult with your pediatrician immediately. They will likely recommend eliminating all suspected foods from your child’s diet for a period of time. Once the problem resolves, reintroduce foods slowly to determine what foods trigger reactions.

Final Thoughts

 The best way to approach preventing food allergies in children is to be proactive. Some research on food allergies has revealed some possibilities, such as breastfeeding, good nutrition, and avoiding certain substances. Additional research will hopefully improve the knowledge in the area of food allergy prevention.

To Your Health!