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Video transcript

so what is allergic rhinitis well the part of the word Rhine comes from the Greek root that means nose like in rhinoplasty or rhinoceros and itís just means inflammation so this is an inflammation of the nose and allergic just means that it's caused by allergies so let's go ahead and draw our nose here now this is the outside of the nose but the inside the nose is covered with a smooth lining and that smooth lining is called mucosa now mucosa lines everything inside your nose but it's not just totally smooth in there there are these bones that stick out that are called Concha they're called Concha because they're kind of coiled like little snail shells so draw those in like this these Concha kind of stick out from the side of the wall and these Concha kind of stick out from the side of the wall of the nose and they can take out and they can take up almost all the space in there but in order to figure out what's happening a little bit better we have to zoom in and we have to zoom in all the way to the level of the cells and so here I'm drawing some of the cells of the nasal mucosa these are big globular pink cells but there's a couple cells in here that are different these are cells of your immune system the ones that we're worried about the immune cells in the nose that deal with allergic rhinitis are called mast cells and basophils so let's say this particular nose in this particular set of cells has allergic rhinitis what exactly is happening well in allergic rhinitis like with any allergy your body has an overreaction to some sort of stimulus in the environment and that stimulus is called an allergen and let's take a little side note here and talk about the allergens that are common to people who suffer from allergic rhinitis the most common culprit is pollen and pollen can comes from trees or grass in fact hay can cause allergic rhinitis and it gives rise to one of the other terms called hay fever although technically allergic rhinitis isn't a fever pollen also tends to be season in other words some types of pollen are out in the spring others in the fall and that gives rise to yet another term that's synonymous with allergic rhinitis or seasonal allergies other things that can act as allergens would be mold or animal dander but basically anything that can get into the air that you can inhale can act as an allergen to somebody who suffers from allergic rhinitis so let's say this nose in this group of cells are out there in the environment doing their thing breathing and suck up something that's going to act as an allergen so that allergen goes into the nose will erase a little bit here and that allergen is going to come into contact with this mast cell over here being a mast cell or a basal fill on its surface it has a particular protein that shaped a little bit like a Y and that protein is called an immune globulin which is shortened to I G and this particular type of immune globulin is called IgE there are other types of immunoglobulins IgG and IgM but for allergic rhinitis we're concerned with IgE this little grain of pollen or whatever the allergen is let's assume it's pollen here it's going to get bound by this IgE molecule and that IgE molecule again just a protein sitting on the surface of this basophils is going to alert that cell to its presence now in a normal person the reaction that that cell has should be pretty minimal I mean it's just a grain of pollen it's not like it's an infectious agent that's going to go in and give your body all sorts of trouble but in a person that suffers from allergic rhinitis this cell over reacts and it overreact big-time and when it sees that pollen grain it starts letting out little molecules into its environment the tell all the cells around it to get excited as well so this whole group of nasal mucosa gets overreacted the most common type of molecule that's used for signaling here is called a histamine so now that these immune cells are overreacting and causing all the cells around them to overreact to this allergen we can predict what is going to happen inside the nose on a larger scale well the first thing is that histamine is going to cause all sorts of problems with inflammation and that can be really severe the mucosa can thicken up big-time and get really engorged and dimittis and swollen and that happens all throughout the nose because these basophils or mast cells aren't just sitting in one particular area they're scattered everywhere I'm going to draw some of this inflammation on these ridges in the nose the turbinates but it's happening kind of everywhere in addition to becoming swollen this mucosa is going to start to over produce mucus and that mucus is going to drip down along the turbinates it's going to drip down the sides of the nose here it's going to form big drips that hang down inside your nose it's going to pool on the base of your nasal cavity here draw a few other drips of mucus now I'm drawing this mucus in green but it's usually actually clear as you know or anybody that suffers with allergic rhinitis nose this can come right out your nose here and of course your nose is not an isolated thing and as this mucus pools in your nasal cavity it's going to head down this way and that is towards your throat so you can COFF this stuff up as well but your throat isn't the only thing that's attached to your nose in fact there's a tube that lives right about here that opens up just underneath this first ridge right about there and as the mucosa swells up it can swell that tube shut and that tube is called the nasolacrimal duct and it connects your nose to your eye and its job is to drain the tears out of your eye and into your nose or you don't even notice them now when that duct gets swollen shut the tears don't have anywhere to go and that's going to lead to watery eyes there's another tube that can be affected at the back of your throat and that tube is connected to your ear and it's called the eustachian tube and similarly if the swelling gets bad enough it can block off the eustachian tube and cause fluid to back up in this and that's going to lead the symptoms with your ear particularly stuffiness and decreased ability to hear of course there's also nerves in your nose I'll draw one of the nerves going off to the turbine in here and these nerves ultimately end in your brain and as they get inflamed with all the processes happening in your nose they become irritated and send signals to your body particularly the signal to sneeze and then if the swelling continues to get bigger and more pronounced and more pronounced it can actually completely block off this entire nose and when that happens even error can't get by and when air can't get by breathing becomes a problem so let's recap the symptoms so first you get swelling and congestion if you block off the nasolacrimal duct you can get watery eyes if you block off the eustachian tube you can get stuffed up ears and that nasal mucosa is continually making mucus and that causes nasal drip the irritated nerves cause sneezing and the block to air passages leads to difficulty breathing through the nose and these symptoms are going to vary from person to person some people's over-reactive immune systems are severely overi active these symptoms are really really bad or they're happening all the time other people may just have a little nasal drip and that's all some people's anatomy may be such that their nasolacrimal duct is easily blocked by just a little bit of swelling and that can lead to really bad watery eyes but not much else it all depends on the person it can happen for a few days if you're exposed just briefly or it can happen year-round if you're allergic to many things that are always in your environment additionally sometimes it's really easy to figure out what it is sometimes it's really hard and you can't ever pin down exactly what it is but if you remember the underlying principles of an ovary active immune cell sitting in your nose and you know a little bit about the anatomy of the nose you can predict all the symptoms that happen in this situation