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Next we'll review some common infectious disorders

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of the large airways.

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These include croup

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or also known as lary, Ringo tracheitis,

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bacterial tracheitis, and epi glossitis.

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This first case is a classic case of croup

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or laryn tracheitis.

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Frequently these patients present with what's described

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as a barking or seal like cough

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and when due to a viral infection.

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These are most commonly in patients

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who are six months to three years of age.

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Outside of this age range, you should think of etiologies

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that might be something different than a viral infection.

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What we see here on this frontal radiograph

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of the nex soft tissues is something different than

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what we discussed in our normal airway section.

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Note the closed glottis and expiration,

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but rather than the normal horizontal shouldering

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of the subglottic area,

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but rather than the normal horizontal shouldering

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of the subglottic airway, instead we have this steep slope

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going down into the rest of the trachea.

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This is what is the classic steeple sign.

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It's the absence of that shouldering on both sides

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and instead the steep slope like a steeple of a church

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On lateral view, we have some imaging features

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that are classically described,

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but I think on a practical level are sometimes

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hard to tease out.

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They include hyper aeration of the hypo pharynx

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with corresponding narrowing in the AP dimension

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of the airway, as well

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as sometimes a soft tissue density fullness in the region

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of the glottis in this patient.

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Notice the normal epiglottis, like I said,

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those findings are sometimes difficult

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or soft findings, so I find

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that the frontal is more useful a lot of the time.

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But in this case, if you see these findings in conjunction

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with those more classic frontal findings,

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then I think that could be helpful.

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Note that this patient has good extension

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with a towel rolled under their neck.

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This is another patient who also has group.

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You can see that their head is being held still

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by adult hands.

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And again, as we zoom in here, we can see a closed glottis

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and we have no normal shouldering of the subglottic airway.

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And instead we have this S steeple slope on the lateral.

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Again, we have good extension in this patient with the aid

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of adult hands, and as I zoom in, you can see

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that there is some increased soft tissue fullness due

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to the inflammation and some slight narrowing

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of the subglottic airway.

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Again, those are softer findings

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and as we saw with our normal cases, even

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with a normal airway in expiration,

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it can sometimes sort of look like this.

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So in isolation those are a little bit

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difficult to tease out.

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But again, in combination

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with this finding on the frontal, this

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Is pretty typical of croup.

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This is another case of croup and I wanted to show it

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because it also shows simultaneously

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that expiratory buckling we discussed

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with the normal airway.

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So this patient is in expiration.

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They have normal expiratory buckling,

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but they have abnormal loss of shouldering

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of the subglottic airway due to the steeping from croup

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on this patient's lateral radiograph, again,

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we have good extension with a towel under the neck.

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I'll zoom in a little bit.

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We don't have prevertebral soft tissue swelling

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'cause we have pretty good aeration of the hypopharynx,

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but again, we see some subglottic narrowing in the AP

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dimension and some soft tissue fullness.

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The next case is in an older patient starting

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with the lateral, we have an unusual appearance

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to the airway with soft tissue fullness

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and some wispy hyperdense lines

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around the glottis

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and the subglottic airway correspondingly on the frontal.

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While a little more subtle,

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you can see in a few different places some

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asymmetric soft tissue nodularity in the airway.

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While this is not a confirmed case,

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this is certainly a possible case of bacterial tracheitis,

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which is also known as exudative tracheitis.

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This occurs in bacterial infections

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that cause purulent tracheal material with exudative plaques

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that adhere to the tracheal walls

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and can cause pseudo membranes to form

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these pseudo membranes as well as the

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exudative plaques can slough off

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and lead to airway obstruction.

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This next case is a patient

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that will start with the lateral.

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I'm gonna zoom in a little bit

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and hopefully you notice right away

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that this patient's epiglottis looks markedly abnormal,

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unlike the normal ones that we've noticed in other patients.

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This patient's epiglottis is very thick.

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This is what's described as the thumb sign where it sort

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of looks like a thumbprint right over the

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area of the epiglottis.

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It has associated thickening

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of the air epigenetic folds as well.

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And this is a patient with epiglottitis.

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Historically, this was most commonly caused by H influenza

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and cases dropped precipitously

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after the introduction of the vaccine

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to this particular pathogen.

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However, nowadays we have more

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and more unvaccinated patients.

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As was the case with this patient who are now susceptible

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to developing epiglottitis as a result

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of H influenza A infection.

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It's really important to know this even though it's still

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pretty rare because if you see this thumb sign

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of epiglottitis, this is a life-threatening emergency.

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This patient needs to be evaluated, if not already

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by an emergency department physician by ENT.

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They will likely need to

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Secure an airway sooner rather than later

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and they can decompensate very quickly.

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It is important once this is recognized

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that the patient not be placed supine

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where they can develop airway obstruction.

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In fact, you may find that

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that they will preferentially lean forward to try

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and get more air in and they may be drooling

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because they can't handle their own secretions.

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So again, this is a life-threatening emergency

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and not something that you ever wanna miss.

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So very important to know the thumbprint sign

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of epiglottitis.

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This patient does have a frontal

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radiograph that I'll zoom in here.

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That's not particularly revealing.

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You can't really see that region as well,

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so it's really important

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to look at the lateral when this is a clinical concern.

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And the final case I'll show you is also of epiglottitis,

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which we don't typically get on a CT scan,

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but we do have in this particular patient,

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this is a teenager.

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I'll start with the sagittal contrast enhanced images

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and we can see the equivalent

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of their radiographic thumb sign is this very emus

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epiglottis as well as the area epiglottic folds.

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So this is a patient who had epiglottitis correspondingly,

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we can see that edema

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and thickening of the epiglottis on coronal

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as well as on axial views.

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It's very emin and abnormal.

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This particular patient did not have H influenza.

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This patient was up to date on their vaccines

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and this is a case just to illustrate that

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although H influenza is the more common pathogen,

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epiglottitis can also be caused by bacteria, some sort

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of mixed infection with bacteria and virus,

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but also non-infectious etiologies including

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vaping and e-cigarettes.

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This particular patient did vape and use e-cigarettes

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and it was thought that their epiglottitis was caused due

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to chemical injury from the vaping as well

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as excessive vomiting as a result of complications.