The sniffling and sneezing from seasonal allergies can drive anyone mad. But these symptoms aren’t just annoying — they also represent a major source of stress for allergy sufferers. With every sniff or sneeze, your immune system responds to airborne allergens by releasing histamine and other inflammatory chemicals in the airways of your nose, mouth, and sinuses. These reactions cause an immediate response called the allergic reaction, characterized by watery eyes, runny nose, itchy skin, and cough. This happens every time you’re exposed to an allergen. But suppose you’ve ever experienced symptoms that seem to come out of nowhere (such as getting hives or rashes after coming into contact with a certain animal or insect).

In that case, you may have an IgE-mediated hypersensitivity to that allergen. That’s when your immune system overreacts to harmless triggers like pollen, dust mites, grasses, weeds, fungi, latex proteins, dyes, and perfumes — rather than reacting to a real threat such as a virus or bacteria. Allergies are complex conditions that manifest differently in different people. However, there is strong evidence that allergies are linked to environmental factors such as dog dander (from dogs and other mammals), house dust mites (from rats), cockroach feces (from roaches), and ragweed pollen (from plants).

Immunology: The science of immunity and inflammation

The immune system protects your body by attacking foreign substances, such as bacteria and viruses, that are trying to invade your body. It also defends against harmful substances in your body, like cancer cells, and autoimmune diseases like rheumatoid arthritis. The immune system is made up of different types of cells. Some cells, like the thymus and spleen, are involved in childhood immunological development. Others, like the skin and gut cells, help the immune system identify and eliminate harmful substances, like bacteria or cancer cells.

In addition, the immune system is controlled by a network of different types of cells, including B cells, T cells, and macrophages. Some of these cells produce antibodies that help to identify and kill intruders. Other cells, called regulatory T cells, tell the B cells to stop producing antibodies and instead help to keep the immune system in check.

The Allergy Process

Allergies are hypersensitivity caused by the immune system overreacting to harmless substances like pollen, dust mites, or latex in your environment. Your immune system may also overreact to certain microbes, like parasites, bacteria, or fungi. When your immune system detects an allergen, it releases histamine and other chemicals, causing symptoms like a runny nose, itchy skin, and watery eyes. When it touches your body, the allergen may cause another allergic reaction, like a rash or skin irritation. Symptoms vary, depending on which allergen triggers your allergic reaction. Pollen is the most common cause of seasonal allergies, followed by mold, animal dander, and dust mites. Some people are also allergic to foods like peanuts, wheat, or milk.

What causes allergies?

Allergies are complicated, but they likely have many different causes, according to Portland, OR allergist. In addition, many people who have allergies have other allergic symptoms, like hay fever or asthma. That’s because allergens are also linked to these conditions. For example, high levels of ragweed, a common allergen, have been linked to aggravated asthma.

Common allergens and allergen-specific food allergies

Some foods, like peanuts and tree nuts, can cause various allergic reactions. Peanuts are a common cause of food allergies, which develop when your immune system mistakes the legume for a virus or bacteria. Food allergies are the most common cause of anaphylaxis, a life-threatening allergic reaction. When someone with a peanut allergy consumes even a tiny amount of the legume, their anaphylactic shock can cause life-threatening symptoms like breathing problems and hives.

The Link Between Immunological Conditions and Allergies

Some people may have a genetic predisposition to develop allergies. About 1 in 13 people has an allergy to various allergens. However, many studies suggest that allergies frequently increase due to environmental changes, including certain microbes and dust mites. For example, a study of dust from the floors of homes in the Netherlands found that ragweed pollen had increased by 40% in the past 30 years. Researchers suspect that ragweed and other weeds and plants are being transported to new areas by human traffic. This suggests that allergies are linked to factors other than genetics. Still, scientists aren’t sure why allergies are on the rise. Possible explanations include changes in the environment and the growth of multinational corporations.

Summary

Allergies can cause a runny nose, itchy skin, and watery eyes. Some people are also allergic to food like peanuts, wheat, or milk. The most common pollen and insect allergens can also cause anaphylaxis, a life-threatening allergic reaction. Allergies are complex conditions that manifest differently in different people. However, there is strong evidence that allergies are linked to environmental factors such as dust mites, house dust mites, animal dander from pets, cockroach feces, and ragweed pollen. Allergies are linked to environmental factors such as house dust mites, house dust mites, animal dander, cockroach feces, ragweed pollen, and certain microbes.