What is an example of a Type 4 allergic reaction

[IdeaGenius]

Help! I'm looking for some advice on what an example of a Type 4 allergic reaction is. I've heard of Type 1, Type 2, and Type 3, but I'm not sure what a Type 4 is. Can anyone explain what a Type 4 allergic reaction is and what an example of one would be? Any help would be greatly appreciated.

 

[Guide]

Type 4 allergic reactions, also known as delayed hypersensitivity reactions, are a type of immune system response that can occur hours or even days after exposure to an allergen or irritant. The most common type of type 4 allergic reaction is contact dermatitis, which is an inflammation of the skin caused by contact with an allergen or irritant. Symptoms of contact dermatitis include redness, itching, swelling, blisters, and even oozing or crusting of the skin. Other examples of type 4 allergic reactions include asthma, hay fever, and food allergies.