What Is Delayed-Type Hypersensitivity? Defining Delayed-Type Hypersensitivity

What is delayed-type hypersensitivity?

Delayed-type hypersensitivity (DTH) is a type of immune response that occurs a day or more after exposure to an antigen. It is mediated by white blood cells called T cells and is characterized by inflammation and tissue damage.

How does delayed-type hypersensitivity differ from immediate hypersensitivity?

Immediate hypersensitivity (also known as anaphylaxis) is a type of immune response that occurs within 24 hours of exposure to an antigen. It is mediated by antibodies and is characterized by symptoms such as hives, swelling, and difficulty breathing. Delayed-type hypersensitivity, on the other hand, occurs a day or more after exposure and is mediated by T cells."

What are some examples of delayed-type hypersensitivity?

Examples of delayed-type hypersensitivity include poison ivy rash, tuberculosis skin test reaction, and contact dermatitis.

What are the symptoms of delayed-type hypersensitivity?

Symptoms of delayed-type hypersensitivity include redness, swelling, heat, and pain at the site of exposure. These symptoms usually peak at 48-72 hours after exposure and can last for several days.

What is the role of T cells in delayed-type hypersensitivity?

T cells, also known as T lymphocytes, play a critical role in delayed-type hypersensitivity. They are a type of white blood cell that are responsible for identifying and responding to foreign invaders in the body. In the case of delayed-type hypersensitivity, T cells recognize an antigen and trigger an immune response that leads to inflammation and tissue damage.

What are the differences between delayed-type hypersensitivity and allergy?

Delayed-type hypersensitivity and allergy are both types of immune responses, but they have some important differences. Allergy is a type of immediate hypersensitivity, which means it occurs within minutes of exposure to an antigen. It is mediated by antibodies and is characterized by symptoms such as hives, swelling, and difficulty breathing. Delayed-type hypersensitivity, on the other hand, occurs days after exposure and is mediated by T cells.

How can delayed-type hypersensitivity be treated?

Treatment of delayed-type hypersensitivity depends on the specific condition and the severity of symptoms. In some cases, treatment may not be necessary as symptoms may resolve on their own. In more severe cases, treatment may include corticosteroids, antibiotics, and other medications to reduce inflammation and relieve symptoms.

What are some common allergens that can trigger delayed-type hypersensitivity?

Common allergens that can trigger delayed-type hypersensitivity include metals such as nickel, cobalt, and gold. Other allergens include certain medications, fragrances, rubber, and certain plants such as poison ivy.