Use the following choices to match the type of hypersensitivit...

Question

Use the following choices to match the type of hypersensitivity to the example in question given below.

a. Type I hypersensitivity

b. Type II hypersensitivity

c. Type III hypersensitivity

d. Type IV hypersensitivity

e. All of the above

Localized anaphylaxis.

Accepted Answer

Hello, everyone. And welcome back. Our next question says allergy from pollen inhalation is an example of which of the following. And we have poor answer choices that are different types of hypersensitivity. So each one says type whatever hypersensitivity choice A is type two, B is type one, C is type four or D is type three. So which type is an allergy reaction from inhaling pollen that you're allergic to? Well, this can seem surprising but it's actually choice B type one, which is anaphylactic, which we're used to thinking of anaphylactic reactions as thinking of the systemic kind anaphylactic shock, which can be deadly. But in this case, the reaction to pollen inhalation is a more localized anaphylactic reaction. This is characterized by being very rapid um as opposed to waiting a little while to show up. And it's caused when the IgE antibodies recognize the antigen. In this case, the allergen and that stimulates mast cells that to release histamine and it's histamine that causes the symptoms. In this case, the symptoms because the allergen has been taken into the body and the upper respiratory tract, the symptoms affect the upper respiratory tract. So the symptoms depend on the part of the body where the allergen enters. So, again, anaphylactic type reactions, uh and things like hay fever and asthma. But also, of course, the anaphylactic shock that occur after consuming a food, someone is allergic to or being stung by a bee or another insect. That one is allergic to the venom. Let's just take a look at our other types of sensitivity to understand why they're not correct choice. A is type two, hyper sensitivity. This is also known as cytotoxic cyber sensitivity. Well, we know we're going to have some cell death happening given that name, this is not as rapid as anaphylaxis. It occurs within a few hours and this when this occurs the encounter with the antigen causes IgM and IgG antibodies to form this activates the complement system and causes the target cells to be destroyed. So this is the kind of reaction and hypersensitivity. You see when you have transfusion reactions. So if you get the wrong kind of blood given to you or Rh incompatibility reactions. So because the it's the red blood cells themselves displaying the antigen when those antibodies bind those cells are targeted for destruction, but that's not what that is not what is happening here. So choice A is not our correct answer. C is type four and type four is known as delayed cell mediated hypersensitivity. In this case, it's delayed because what's happening here is that these reactions occur when there's a second encounter with an antigen. So the body's already been sensitized to something. And in that second encounter, memory T cells are activated, we often think about memory b cells, but there are memory T cells. And when they are, when they bind and are activated, they release cytokines. These cause the release of macrophages and promote inflammation. So it causes this inflammation reaction. It can also cause a more serious reaction if it activates cytotoxic T cells. And that happens in a case of one type of type four hypersensitivity, which is transplant rejection. So, if the organ that is transplanted doesn't, isn't as good good enough of a match body rejects it. This is what happens there. Cytotoxic T cells begin to attack the cells of the donor organ. This also occurs in the more mild form of contact dermatitis and in certain diseases, which is why you can test for exposure to tuberculosis with a test that looks at inflammation after exposure to some parts of the tuberculin bacteria. But this is not what's going on with our inhalation of pollen. So not our answer. And then finally, we have choice D which is type three hypersensitivity, also known as immune complex hypersensitivity, which gives us a pretty big clue what it does. And in this form, the antibodies and antigens, when antibodies encounter the antigens form a complex sort of a big snarl of antibodies and antigen bound together that in itself causes damage and inflammation in the tissues. And this type of reaction occurs in what's called the Arthus reaction. It occurs in serum sickness and perhaps more well known it occurs in rheumatoid, rheumatoid arthritis causes the symptoms there, but it's not what we're looking for. So it's not our answer. So once again, the allergy symptoms that result from pollen inhalation are an example of choice B type one hypersensitivity. See you in the next video.

Use the following choices to match the type of hypersensitivity to the example in question given below.
a. Type I hypersensitivity
b. Type II hypersensitivity
c. Type III hypersensitivity
d. Type IV hypersensitivity
e. All of the above
Localized anaphylaxis.

Key Concepts

Types of Hypersensitivity Reactions

Type I Hypersensitivity (Localized Anaphylaxis)

Immune Mechanisms Underlying Hypersensitivity Types

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