Allergic rhinitis diagnosis and treatment | Respiratory system diseases | NCLEX-RN | Khan Academy
24
August

By Adem Lewis / in , , , , , , /


– [Voiceover] How does somebody get diagnosed with allergic rhinitis? Well, allergic rhinitis is
actually a very common disease, and most clinicians are
very used to seeing it, and so far and away, the most
common way to get diagnosed is actually by history and exam. If a person is displaying
all the symptoms, then the diagnosis of allergic
rhinitis can be very easy. For example, if they
have nasal congestion, if they have nasal discharge, if they have watery, itchy
eyes, if they have sneezing. It becomes even easier if you
can show that those symptoms are seasonal or a person actually can show that they react to a specific allergen. In these situations, allergic
rhinitis is easy to diagnose, and oftentimes, they’ll
be treated successfully from this point on, but what
if there’s still a question? What if, for example, they
don’t have a seasonal component, or they only have watery
eyes and sneezing? In that case, more information is needed. Oftentimes, the next go-to test is something called skin testing. Now, skin testing may
sound a little barbaric when I describe it, but it’s
actually the most sensitive and probably the most specific way, other than history, to get at the diagnosis of allergic rhinitis. In order to undergo skin testing, the patient has to have
a relatively large patch of skin available for the test. Usually this is done
on the patient’s back. This can also be done on the arm or any other large area, but the important thing is
that the person has enough room to place multiple tiny
little pricks on the skin, and each one of these
pricks contains an allergen. In other words, each one of these contains something that the person
might be allergic to. Here, I’m going to draw a few
out on this patient’s back, and usually the person
that’s performing this test will number these with a
Sharpie or a ballpoint pen just so they can keep them straight so they know exactly what
it is that’s going on. After the allergens are placed on or actually within the skin,
15 minutes is allowed to pass. At this point, the skin has
had enough time to react to any of those allergens that a
person might be allergic to. For instance, if this
person has a skin wheal here and a skin wheal here, the
person that performed the test knows one particular allergen here and one particular allergen
here are potential culprits. Now, yes, this will leave the patient with an itchy, red,
inflamed patch of skin, but it usually doesn’t last that long, and this can give valuable information into what might be causing
the patient’s symptoms. For instance, in the
scenario that I’ve drawn, if the person has a cat at home, it may be that the cat is what’s causing the patient’s symptoms,
or it could be as simple as taking a different
route walking to work and avoiding that patch of grass which is currently distributing
pollen into the air. Now, sometimes nothing that the patient has been exposed to reacts,
or there’s another question about what could possibly be going on, and the skin test is equivocal, or perhaps the patient
wouldn’t tolerate having the skin testing, is either very young or has a skin condition that would preclude putting these allergens down. In those situations, you might need to go on to blood testing. Blood testing can be
performed by almost anybody. Yes, it involves a needle stick. Yes, people don’t like
having these types of tests, but it might be preferable
to the skin testing option. Sometimes also, it may
be that you’re worried that there could be a dangerous
reaction to the skin test, and the blood test needs
to be performed instead. Blood tests in the setting of allergies basically all look for the same thing. They all want to know are
there specific antibodies to any of these allergens
in the patient’s blood, and the specific antibody
that we’re looking for in the case of allergic
rhinitis and most allergies is called immunoglobulin or IgE. Now, your body makes a whole lot of different IgE molecules or proteins, and each IgE is specific
for a certain thing. In other words, each antibody will bind to a specific allergen, so
a person that’s allergic to cat dander, for
instance, would have IgE circulating in their blood
that would bind to cat dander. Now, the first one of
these tests to be developed was called a RAST test, or R-A-S-T, and RAST stands for
radioallergosorbent test, and I’ll write that out here. Now, we won’t go into too
much more detail because RAST tests have essentially
been completely replaced by a newer and more sensitive
test that uses fluorescence, or alternatively, another
test that uses enzymes. The enzyme test is also
known as an ELISA test, or enzyme-linked immunosorbent assay, and it’s worth spending a second on what these tests actually do because they’re kind of interesting. There are various companies
that have developed these tests, and the general idea is that they provide a solid substance, and
within that substance are embedded certain allergens. In this case, let’s say it’s pollen. This might be in a test
tube or on a little plate, and usually a number
of different allergens are tested at once, but once
you’ve got your allergen embedded in a solid substrate, you wash it with the patient’s serum. Within the patient’s serum are those IgE molecules that
we’re talking about. IgE molecules are shaped like little “y”s, and they bind the allergen or potentially bind the
allergen, so the serum is washed away at this point, and you’re left with your solid substrate, your bound allergens,
and your IgE molecules. The next step is that the manufacturer provides another antibody,
but this antibody actually binds to those IgE molecules. Again, they’re shaped like little “y”s, and the manufacturer has
produced these to either have an enzyme, in the case
of the ELISA, or to have a little fluorescent molecule
on the tip of them here. Using the activity of that enzyme to change a solution’s color or by looking at the fluorescence of this little fluorescent molecule, they can actually tell
how much IgE is bound, and that can give them the idea that in this particular patient’s blood, there was IgE that bound to pollen. That means they’re allergic to pollen, or at least potentially it does. Both skin tests and blood
tests can have false positives, and they can’t be interpreted in a vacuum. It will show that a
person might be allergic when they actually aren’t, or false negatives, it will show that a person’s not allergic
when they actually are, but together with a history, and potentially with skin testing, the blood test can be a
very useful alternative. Now, because this had to
go through a lot of steps and a lot of development, of course, these blood tests are expensive, and that’s one of the main
drawbacks, in addition, of course, to having to actually
get the patient’s blood. Let’s say a person has
gone through this process and at this point, they’ve nailed down the diagnosis of allergic rhinitis. What’s next? The next step is treatment. For discussion of treatment, let’s zoom back in to the cellular level. Here, I’m going to draw the
nasal mucosal cells again, all lumped together, and I’m going to draw one special cell, and that’s
our overreactive immune cell. Of course, there are lots
of these in the nasal mucosa in a person who is allergic to things, but we’re just going to draw in the one. Remember, this cell is usually
a basophil or a mast cell. Let’s say this particular
cell is overreactive and sensitized to this allergen here, which we’ll say is pollen. This cell is expressing that IgE molecule, and that pollen is going to go in and be bound up by that IgE. When that pollen binds to the IgE, it signals to the cell to react. Of course, in allergies it’s
going to be over-reacting. This brings up our first
potential treatment. Our first treatment is
to avoid the allergen. That will put a block in
the process right here. I’ll draw that in as a
little bar blocking the way for this pollen to get bound
up by this IgE molecule. In the case of pollen, it may be avoiding going outside when there’s
a high pollen count. In severe cases, you may have to relocate to areas where the
pollen isn’t even there. Sometimes it’s impossible to do this, for instance, in the case
of a loved family pet, or if you’re not exactly
sure what the allergen is. It’s good that we have other treatments. Let’s talk about the next
step in this allergic cascade. Well, remember, when this
cell overreacts to the pollen, it’s going to start to release
inflammatory molecules, and it’s going to release them
to all its neighboring cells, causing them to overreact as well. It’s going to allow blood
vessels to get leaky and for things to get swollen. It’s going to cause these
cells to overproduce mucus and all the other things that go along with allergic rhinitis. All those things are a result of these inflammatory molecules that this cell is putting out. The best and most potent next treatment after avoidance is to
decrease the inflammation. There’s been numerous studies that show that the best way to do this is steroids. In most cases, the steroids are applied directly to the nasal mucosa. Steroids have complex mechanism of action, but the end result is to
decrease inflammation. Sometimes, though, it’s not enough, and we have to attack other targets in this pathway of inflammation. Remember, this immune cell is overreacting and sending out all these
pro-inflammatory molecules. Well, probably the most important
one is called histamine. It’s one of the major players in causing all of the inflammation, but these cells have to
detect the histamine, but they have a little
receptor that’s sitting here on their membrane that’s
specifically built to receive histamine and react to cause all this inflammation. This receptor is called an H1,
for histamine one receptor, so our next line of attack
against this inflammatory pathway are called antihistamines,
and that H1 blocker gets right in the way of that process here where the histamine
binds to the H1 receptor. In fact, we can draw in boxes everywhere there’s a histamine molecule coming in to affect to these
cells, but unfortunately, that’s not the only
pro-inflammatory molecule out there. These cells are producing other molecules that go off and affect the nasal mucosa and the surrounding tissue as well. Another molecule that’s
involved in this pathway that we have a drug against
is called a leukotriene. Just like with histamine, there are little leukotriene receptors as well, sitting on the cell surface. Our next line of treatment,
although getting to be kind of last-ditch at this point, are called leukotriene inhibitors. Leukotriene inhibitors
actually have a variety of different targets that
can work like the H1 blocker right at the site of binding, like this. They can also work inside the
cell later on in the pathway of a leukotriene’s mechanism of action. We’ll draw some blocks here
within some of these cells. Most studies have shown that
these leukotriene inhibitors aren’t quite as effective,
but they do give us another way to treat allergic rhinitis, especially if the first
two methods aren’t working. Once you have your diagnosis
of allergic rhinitis, always not doom and gloom, we have an effective treatment regimen
that we can put into action.


14 thoughts on “Allergic rhinitis diagnosis and treatment | Respiratory system diseases | NCLEX-RN | Khan Academy

  1. Sir. antihistamines and leukotriene for allergy rhinites treatment?, sir can i know the name of that medicines in drugs store?

  2. btw the netti pot is very useful… use it in the morning and before bed and you should see a difference. I see it like brushing my teeth.. if i dont brush my teeth they will go yellow and ill get cavities. If i dont use the netti pot to clean the nasal passages… well im going to get a reaction. Keep the nasal passages clean with water and a neti pot. No one wants to have steroids sprayed up their nose all the time. Of course i have rhinitis all year around due to dust mites… specifically a protein in dust mite shit… so you can imagine how hard that is to avoid… its in the air. NETTI POT give it a try

  3. Very nice…. reading about this has been rather confusing. You made it easy to understand. Now I understand why the Nasal Steroid is the first treatment (aside from avoiding allergen). Likewise, I also watched the other video and understood the symptoms.
    Sincerely thankful.

  4. Here is the deal. I only have a bachelors of arts in biology minor in psychology (also took classes on existentialism, morality, sociology and technical communication). I also have allergic rhinitis year round because of bed mite shit in the air. Please lets work our minds together. Can antihistamines can leave one suceptible to cancer? Can steeroid creat a dependency and make it worse? What is the point of these medications if our body is prone to fall again and again?

    On the other hand, we have diet, alkaline (plants honey, raw) vs acidic (sugars, flours, prosessed)…the best treatment is actually an alkaline diet such as, chewing raw onions, garlic, ginger, turmeric, honey and others. One can juice them to make an elixir. So avoid the acidic diet, such as pizza, cheese, milk, fried chiken, muffins, cookies, cakes, etc. Consider that not consuming the cheap food contributes to decreasing rich fast food restaurants like Mcdonalds, Burguer King, Pizza Hut, etc, AND consuming raw veggies from local farms contributes to increasing the income of local farmers.

    I believe this to be utopic by eliminating income inequality, and eliminate costs on inefective medicine (not that all medicine is inefective of course). Also transportation cost, such as gas and smoke are avoided. However, the downpart would be the loss of confort, caprices and dependence on a fast pace life style. Notice how the point is to make all of us more altruistic and less despotic. Please let me know if Im crazy.

  5. Anyone know what is Sinuzolax Miracle about? I hear many people cure their sinusitis naturally with Sinuzolax Miracle (do a google search).

  6. I read many superb opinions on the internet about how Sinuzolax Miracle
    (look on google search engine) can assist you cures your sinusitis
    safely. Has anyone tried this popular sinus infection home remedy?

  7. how bout mix rhinitis? a mix of vasomotor and allergic rhinitis??
    tbh i hav been suffering from swollen turbinates for 6months already and hav been using flo nasal rinse and nasonex since january , no nasal discharge, nose popping sound , blocked nose….i dunno wht to do tbh,….since there are times when the turbinates get so big that they will hit my nasal septum causing me alot of facial pain and surgery is not a option for me because i dont want empty nose syndrome…….since there are people who hav their turbinates reduced by 10% and still developed that condition….anyone suffering from the same thing as me??

  8. This video is BULLSHIT! How many patients have you actually "CURED" or "HEALED" from allergic rhinitis using steroids? Dont bullshit us man!

  9. There are several factors in reducing nose polyps quickly . One resource I discovered which succeeds in merging these is the jits polyp plan (check it out on google) definately the best plan that I've heard of. look at the great information .

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