Asthma

Asthma is a chronic disease that affects the lungs and makes it harder for people to breathe. Asthma affects approximately 8% of the United States population.

People with asthma typically have times where they experience chest tightness, wheezing, coughing, and shortness of breath. This is caused by a tightening of the airways, making it difficult for air to get into and out of the lungs. We know that asthma symptoms can be made worse with viral infections (common cold), exposure to allergens (like dust or pollen), and irritants in the air (like pollution). We also know that several medicines can make asthma symptoms better. However, there is a lot more to learn about how and why asthma develops, how it changes over time, how to prevent asthma attacks, and how to stop asthma from developing in the first place.

Allergy

Allergies happen when the body's immune system reacts to things in the environment that are typically harmless.

Examples include pollen, dust mites, cat hair, dog hair and various foods. Allergies may cause only minor symptoms but can also be more severe, limiting people's daily activities. Very severe allergies, most usually to foods or insect stings, can result in anaphylactic reactions. Anaphylaxis is a serious and potentially life-threatening event involving multiple body systems.

Respiratory Allergies

A respiratory allergy is an allergy caused by something in the air, such as grass or tree pollen, dust mites, cats, dogs, mold, cockroaches, or rodents. Respiratory allergies that cause symptoms in the nose are also referred to as allergic rhinitis. Approximately 15-20% in the United States population is impacted by allergic rhinitis. This can be seasonal (like hay fever) or year-round, depending on the kind of allergen that causes it. If allergy affects the lungs, symptoms of asthma can develop; this is also referred to as allergic asthma.

Allergic rhinitis can be controlled with various medications, several of which are available over the counter. However, we need better treatments for difficult-to-control allergies. There is also a need to better understand why respiratory allergies develop in order to prevent them early in life.

Food Allergy

A food allergy happens when the body's immune system reacts against an otherwise harmless food. For some people with food allergies, eating even a tiny amount of the food can be dangerous. The most common food allergies are to milk, egg, peanut, tree nuts, soy, wheat, fish, shellfish, and sesame.

Food allergies affect approximately 8% of children and 10% of adults in the United States. Currently, there is no reliable way to predict early in life who will suffer from food allergies. It is also hard to predict if a food allergy will go away on its own, or if new ones will appear over time.

Allergic reactions to foods may include symptoms like rashes with bumps or hives, swelling, stomach pain, or vomiting, but can also include dangerous symptoms affecting breathing and blood circulation. Anaphylaxis is a severe, potentially life-threatening allergic reaction. It is important to understand that not all food reactions are due to allergy, and that special testing may be needed for the correct diagnosis.

Beyond avoiding the problem foods, some treatments for food allergy are now available. We also now know that introduction of some foods in the diet early in life (particularly peanut and egg) could prevent the development of allergy to these foods.

A lot more research needs to be done to better understand the causes of food allergy and to develop more strategies for diagnosis, prevention and for additional treatments.

Atopic Dermatitis

Atopic dermatitis (AD), or eczema, is a chronic skin condition causing itchy, dry, cracked skin. AD affects approximately 11% of children and 9% of adults in the United States. AD appears most frequently in early life. It can be complicated by skin infections and is often seen alongside allergic diseases, particularly food allergies. The cause of AD is not known, but it may involve problems with the function of the skin as a barrier and the immune system.

Mild AD can be treated with moisturizing creams and over the counter topical steroids, but severe AD often requires stronger medications. Several new medications have been recently approved for severe AD. Currently, research focuses on early treatment to prevent severe symptoms and their consequences, such as skin infections.

Allergen Immunotherapy

Allergen immunotherapy is a type of treatment for specific allergies. During allergen immunotherapy, you are given small, controlled amounts of your allergens (things you are allergic to), and your body becomes less sensitive over time. The doses start very small and may increase over time depending on the type of immunotherapy. Currently, allergen immunotherapy is used for the treatment of respiratory allergy, food allergy, and allergy to insect stings.

For respiratory allergy, immunotherapy can be given as tablets under the tongue or injections. For food allergy, immunotherapy can be given as liquid or powder for ingestion. Allergen immunotherapy can cause allergic reactions as a side effect and should be done under a doctor's care.

Research focuses on the development of more effective, longer-lasting, and safer forms of allergen immunotherapy.

Microbiome

The term "microbiome" refers to the entire population of microorganisms that live on and in our body. The microbiome of the human body contains nearly 40 trillion microorganisms, such as bacteria, fungi, and viruses, which are too small to be seen with the naked eye.

Many scientific studies suggest that the microbiome plays a significant role in health and illness. A healthy microbiome can protect us from disease and contribute to healthy bodily functions, while an unhealthy microbiome may play a role in human illnesses, including allergic diseases.

Some NIAID-funded networks conduct research into how specific microorganisms or an overall different microbiome may be connected to allergic diseases. For example, specific microorganisms on the skin and the chemicals they produce may play a role in atopic dermatitis, while some microbial communities in the gut may be related to food allergies.

There is much to learn about the complicated arrangement between the human body and its microbiome in health and disease.