Allergies and Immune System

Allergies are caused by an overreaction of the immune system to something harmless. In children, allergies are often triggered by foods, pets, pollens, molds, and dust. There are two types of allergies: IgE-mediated (or Type I) and non-IgE mediated (Type II). Both types of allergies cause inflammation of the mucous membranes lining the respiratory tract. Symptoms may include sneezing, runny nose, watery eyes, coughing, wheezing, and asthma.

Immune System:

The human body's defense mechanism is called the immune system. It consists of many different organs and cells that work together to protect us from harmful substances. The immune system is divided into three parts: innate, adaptive, and humoral. Innate immunity refers to the first line of defense against pathogens. Adaptive immunity involves memory B cells, T cells, and antibodies. Humoral immunity involves plasma cells, immunoglobulins, and complement.

 Immunization:

Immunizations are medical procedures designed to prevent disease. Vaccines are given to people who have not been exposed to certain diseases. Immunizations are administered either orally or injected. Oral vaccines are taken by mouth while injected vaccines are given directly into muscle or under the skin.

Food Allergies:

Food allergies occur when the immune system reacts to food allergens. These allergens are proteins that are present in some foods. Common food allergens include milk, eggs, peanuts, wheat, soybeans, fish, shellfish, tree nuts, and fruits. Food allergies can affect anyone at any age, although they are most common among infants and young children.

Asthma:

Asthma is a lung disorder characterized by breathing problems. People with asthma experience shortness of breath, chest tightness, wheezing, coughing, and difficulty sleeping. Asthma occurs when the airways become inflamed and swollen. Inflammation triggers the release of chemicals that narrow the airway passages.

Hay Fever:

Hay fever is a type of allergic rhinitis. It is caused by pollen from grasses, trees, weeds, and other flowering plants. Pollen grains land on the outside of the nasal cavity where they stick to mucus membranes. When the pollen comes in contact with the mucus membrane, it releases histamines, which cause the symptoms of hay fever. Hay fever is most common between spring and fall.