Articles, Blog

Allergic Rhinitis – causes, symptoms, diagnosis, treatment, pathology

August 17, 2019


“Rhin” refers to the nose and “itis”
refers to inflammation, so rhinitis is nasal inflammation. Allergic rhinitis is also called hay fever,
because it’s typically caused by allergens like hay, as well as pollen, dust, animal
hair, or mold spores. Since the main trigger is pollinating plants,
allergic rhinitis will flare up at specific times of the year. Allergic rhinitis is a type 1 hypersensitivity
reaction, which is a type of allergic reaction that starts with exposure to an environmental
allergen. So – let’s say that a bit of pollen enters
the nose. It can get picked up by a dendritic cell which
is a type of immune cell that gobbles up foreign particles and presents it to a nearby lymphocyte
called a T cell. If that T cell gets activated, it kicks into
action, producing cytokines which helps to get other immune cells involved. The exact type of T cell determines the type
of immune response, and in allergic rhinitis there’s a bit of a T cell imbalance. There are too many T cells that, when activated,
stimulate B cells, another group of lymphocytes, to produce IgE antibodies. Those IgE antibodies get released into the
bloodstream and bind to mast cells, which are immune cells in the tissue that carry
within themselves a load histamine. Once bound by IgE the mast cells are “primed”,
meaning if pollen enters the body again in the future, those mast cells degranulate and
release their histamine into the local tissue. The histamine causes blood capillaries to
dilate and become leaky which brings more fluid and immune cells to the area where the
mast cells are located. Because the eyes and nose are portals of entry
for infections, there are lots of mast cells around those areas for extra protection. So those IgE-primed mast cells release their
histamine, which causes nearby capillaries to dilate – flooding the facial tissues with
fluid. Interestingly, there’s evidence that early
exposure to allergens might protect against type 1 hypersensitivity. For example, children who grew up on farms
and have pets at an early age typically have lower rates of allergic rhinitis. It’s thought that a combination of genetic
factors and environmental factors like these contribute to which type of T cell group is
most common and thereby influences the overall immune response. The symptoms of allergic rhinitis are related
to the excess fluid in the facial tissues. It causes nasal congestion, and red, itchy,
swollen eyes with frequent bouts of sneezing. Symptoms can begin just minutes after exposure
to allergens, and can persist for weeks at a time, affecting the ability to concentrate
and sleep, as well as attend work or school. The diagnosis of allergic rhinitis is generally
based on simply the way the skin looks, and when possible, it’s helpful to identify
the allergic trigger so that a person can avoid them in the future. One way to identify an allergic trigger is
with SKIN-PRICK test where small drops of allergens are placed on the skin and then
pricked into the skin with a tool; again, to see if there’s evidence of an allergy
like raised bumps or weals – otherwise known as itchy red skin. These tests can test for many allergens at
once, but they can sometimes have low sensitivity and low specificity. In other words, sometimes a person might have
no allergic reaction on the skin test, but have a localized allergic reaction affecting
the nasal cavity and eyes – that’s low sensitivity. Other times a person might have a skin reaction
to something, even though they don’t normally have symptoms when they encounter that allergen
in their everyday life – and that’d be low specificity. Typically, the best thing for allergic rhinitis
is to simply avoid the triggering allergen if possible. If there are symptoms, antihistamine medications
can be used to suppress the effect of mast cell degranulation. Nasal irrigation can flush out the sinuses,
reducing the congestive symptoms of allergic rhinitis. In some situations, it’s also possible to
rewire the body’s immune response to an allergen by exposing it to micro-doses and
slowly ramping up to a full dose of the allergen. This gradually boosts tolerance to the allergen
by reducing the immune system’s tendency to produce IgE each time. Alright, as a quick recap – allergic rhinitis
is a type 1 hypersensitivity reaction which results in inflammation of eyes and nose. Airborne allergens like pollen, dust, animal
hair, or mold spores cause mast cells in the tissues to release histamine, causing the
eyes and nose to get inflamed and watery. Avoiding allergens is the best approach, but
it’s also possible to use antihistamines, and in severe cases try desensitization to
reduce or eliminate the symptoms.

34 Comments

  • Reply Osmosis December 12, 2017 at 7:31 pm

    Hi Folks! We're re-releasing this video to correct an error in our diagnosis section. A previous version of this video discussed the use of a patch test which is specific for Type IV hypersensitivity reactions, not type 1 hypersensitivity reactions.

  • Reply kiera mazmi December 12, 2017 at 8:21 pm

    Tq! Really love the videos you guys released.it makes learning more interesting n fun

  • Reply M-z Ahmed December 12, 2017 at 8:52 pm

    Really love the videos

  • Reply Asmaa Osama December 12, 2017 at 9:17 pm

    Thanks guys!
    I have a question, In case of using antihistamine and it's not really working..so the person is using nasal drops frequently..and he's almost lost ability to smell..what's the solution to that?

  • Reply 예린Yerin December 12, 2017 at 11:03 pm

    Relatable

  • Reply PEACHES PLUMS December 13, 2017 at 5:48 am

    I have this and its soooo annoying! Chlorpheniramine to the rescue!

  • Reply Taha K. December 13, 2017 at 7:53 am

    Really great video with drawing which is nice way of mind mapping

  • Reply Uday Sagar December 13, 2017 at 9:19 am

    Could you please explain in detail about the treatment part in videos.🤗

  • Reply Rue Mubarak December 13, 2017 at 3:13 pm

    really great job … keep it up👏👏👏

  • Reply emma pong December 13, 2017 at 4:13 pm

    love your videos like colourful and clear

  • Reply Cameron Alexander December 14, 2017 at 1:21 am

    So why don't we call it hay, pollen, dust, animal hair and mold spore fever?

  • Reply vip p January 17, 2018 at 2:35 am

    plz.. upload more videos abt ent..

  • Reply Mostafa Elsersy January 17, 2018 at 10:00 am

    Why you didn't mention steroids ?

  • Reply Josephine Calleja January 24, 2018 at 6:17 pm

    I'm 20 years old , I was diagnosed with Rhinitis (that's what the ENT doctor said i have )at the age of 15 years old but i had it way before probably when i was 6/8 years old , I was told that If i wanted surgery i had to wait until i turned 18 years old but i didn't do it. Mine is really unpredictable especially under sun rays really hot and when the temperature is really cold. however mine is always crystal clear. I always carry with me packets of tissues when I'm outside. I used to use Ocean spray but then tried haysan spray and now i want to try others to see what best works for me.

  • Reply Dalia Aissa March 26, 2018 at 6:32 am

    That most effective explanation for Allergic Rhinitis, and this diagram is so helpful for memorizing quickly and understanding very well. THNKS

  • Reply Dale Gab March 30, 2018 at 11:45 pm

    I dont agree! It is not caused by outside factors. Outside factors just triggers it but it is not the ROOT CAUSE. Root cause is internal, in the immune system itself.

  • Reply Dita cantik April 12, 2018 at 11:58 am

    bahasa indonesia please

  • Reply star vaga April 27, 2018 at 11:13 am

    i cant tolerate any fragrance ,dust… i cant even touch the clothes inside my wardrobe as i feel that specific cloth smell and the i sneeze. i cant even tolerate air, a running fan. if someone passes by me, i feel that too as my nostril feels the air and i start sneezing… if i am sitting, then standing or walking will also trigger my nose as one of my nostrils is too sensitive that time. i cant even move then due to the feel of air on my nostril. i cant even wash my face, as my nostril feels water being poured on it and i sneeze then. i cant take anything being cooked in the kitchen as spices and that aroma makes me sneeze. i cant even press washed clothes as i feel surf fragrance from them when they being pressed. i cant even tolerate if something is being moved (any blanket, cloth) around my surrounding or someone being passed by or me mysellf if moves… what is this all? PUTTING RUMAL (handkerchief) DOES NOT WORK IN MY CASE until and unless i make a ball of that cloth and keep on pressing it on my nose with full force so that i cant breath throuth it +it has no contact with the environment… what is this all?

  • Reply Charlotte Haine May 14, 2018 at 8:51 pm

    I want to let you know that i have had those symptoms for a VERY long time i have seen a doctor and there sending me for a skin prick test and the suggested it might be rhinitis thx!!!!!!

  • Reply ro ja June 1, 2018 at 7:11 am

    Make video about the whole anatomy pre clinical subjects too

  • Reply wardayani akib July 17, 2018 at 8:13 am

    Subtitle in Bahasa please

  • Reply Disabler July 29, 2018 at 4:40 pm

    This is based on fake science..

  • Reply Timothy Lewis October 5, 2018 at 8:27 pm

    Can you do one of immunotherapy ?

  • Reply SilkNCookies October 12, 2018 at 2:42 am

    Please do one of these on Sphenoiditis! This is great.

  • Reply HolaNiña Navarro November 10, 2018 at 12:08 pm

    I have allergic rhinitis

  • Reply high tide low tide November 14, 2018 at 11:40 pm

    Incredible no cure for allergies but there's a cure for deadly diseases like hep c and HIV. This is a simple reaction by the body yet they push all these shitty allergy pills and sprays that don't do shit. Allergies have ruined my quality of life and gets worse with age

  • Reply yogesh kumar November 25, 2018 at 3:25 am

    Homeopathy helped me to fight with this…

  • Reply Taqqi Raja December 4, 2018 at 5:20 pm

    this shit fucks up my winters….does anyone also have this?

  • Reply Aly December 30, 2018 at 2:05 am

    MY EYES SWELL UP ALMOST EVERY WEEK MY DOCTOR SAYS ITS ALLERGIES

  • Reply Joseph P Phiri January 2, 2019 at 6:13 am

    Thumb up 100%

  • Reply Kimmy Vlogs January 19, 2019 at 5:20 pm

    I have grow up in farm with cats and dogs as pet but after 20 years, One day, i just suddenly sneeze in my boarding house and that sneeze always happen every day. BEFORE I go to bed and after I wake up. SOMETIMES I SNEEZE IN AFTERNOON WHEN I INHALE SOME PERFUME or JUST A RANDOM SNEEZING. Tbh, this is very annoying and to tell you that in my place, having check up in a doctor is fcking expensive and I am just a broke student. THIS IS WHY NO MATTER HOW I WANT THIS TO END, I STILL NEED A JOB AND SAVE uP SO I CAN FINALLY CHECK THIS STUPID ALLERGY. I DONT REALLY UNDERSTAND WHY I GOT THIS BUT ITS SUPER ANNOYING. SOMETIMES I COULDN'T SLEEP ECAUSE I COULDNT STOP SNEEZING. I really hate this.

  • Reply Joe Arvallo February 3, 2019 at 1:34 am

    Vaccine cause us to have all these symptoms Rrrrrrrrrrrrrrrrrrrrrrr. Two words COLLOIDAL SILVER. Add MARIJUANA TO THE MIX YOUR ON YOUR WAY TO RECOVERY

  • Reply Celestes Evelyn March 9, 2019 at 12:38 am

    I’m so tired of this 😭 I was diagnosed with allergic rhinitis at the age of 13. I’m 23 now. I’ve struggled with breathing since then. I’ve tried everything. I don’t have the same symptoms as other do though. I don’t get the constant sneezing or itching. It’s rare when I do. But i do have excessive post nasal drip. I choke all the time because of it. The nasal drip piles up deep in my throat causing me to hack it out all the time. I’m so tired I just want to be able to breathe 🙁 my nostrils are inflamed every single day of the year. I’m currently on montelukast, Flonase, and Allegra-D. It doesn’t help though. It’s so hard to take a deep breath and my chest feels super tight. Someone help 😭

  • Reply Miyuki Mariano July 29, 2019 at 1:53 am

    I always sneeze specially when cleaning the house, and now I have difficulty in breathing when sleeping or even laying. I feel like there's something hinder my Nose so I breath with my mouth but I learnerd that it is not good. Maybe I have an allergic rhinitis.

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