Type 2 Inflammation Defined

Type 2 inflammation is a term given to a type of immune response that is seen very commonly in allergic disorders. This immune response is thought to play a role in protecting people from certain infections (for example, parasitic infections), but when it is excessive, it may lead to the occurrence of allergic disease. A type 2 immune response involves a certain kind of white blood cell, helper T-cells (also called Th cells) which can influence the amount of inflammatory chemicals (also called cytokines) in the blood, including Il-4 (interleukin-4), Il-5 and Il-13. This immune response can then affect the amount and behavior of other cells, such as mast cells, eosinophils and antibody producing white blood cells (B-cells).

An excess of type 2 inflammation is commonly seen in many allergic disorders, including allergic rhinitis, asthma, food allergy, eosinophilic esophagitis, eczema (atopic dermatitis) and chronic rhinosinusitis with nasal polyps. Diagnosis of these disorders will often depend on the presence of type 2 inflammatory markers (for example, skin tests or blood eosinophil levels), and the treatment is heavily influenced by a medication’s ability to decrease type 2 inflammation. Newer medications, called biologics, specifically target type 2 inflammatory mechanisms to treat allergic diseases.

While not all allergic diseases are caused by type 2 inflammation (for example, not all cases of severe asthma are type 2 in nature), it is usually the underlying basis for most allergic conditions.  

The AAAAI's Find an Allergist / Immunologist service is a trusted resource to help you find a specialist close to home.


5/19/2025