Thread by @nsrosenberg

Another new diagnosis I had never heard of until this pulm rotation: Ulcerative Bronchiolitis (yup, you saw that right). 🧵of an illness script of a rare condition!

Inspired by @EmmGeezee's comments here

https://twitter.com/EmmGeezee/status/1324928165207216128?s=20

#MedTwitter #tweetorial

Background: although called "Inflammatory Bowel Diseases", Ulcerative Colitis and Crohn's Disease do not spare other organs. Some examples:
▶️Rheum: Vasculitis, Arthritis
▶️Skin: Psoriasis, Erythema Nodosum...
▶️Neuro: Encephalitis
▶️Optho: Uveitis

and many more!

Lets focus on the Lung: UC in particular can affect a bunch of "aireas" (🥁):

▶️Upper Airway: Tracheal Stenosis (subglottic)
▶️Lower Airways: Most common = Bronchitis and Bronchiectasis, then rarely Bronchiolitis, Bullous Disease, OP, Vasculitis, and Eosinophilic Disease.

Within this, I wanna talk about bronchiolitis, inflammation of the bronchioles, what we are currently worried about for my patient.

There are two theories, but the one I highlight here is Immune stimulation that causes colitis does the same with the cells in the lungs that share antigens

Again, @EmmGeezee get's the shoutout on her tweet noting the lung and colonic epithelia come from the primitive foregut.

Presentation: often, this may present with dyspnea and cough, but generally non-specific symptoms. There may be an underlying history of bronchiectasis, so a history of chronic productive cough may be present and this might seem like a bronchiectasis exacerbation!

Imaging: you will see centrilobular ground glass opacities and tree in bud opacities

This goes back to the Secondary Pulmonary Lobule, the basic unit of what we can see with our naked eye. Things that affect the artery/lymphatics/vein will fill up the septa first, while the small airway disease may affect the alveoli first, and appear centrilobular.

And while we are here, plug for @Sophia_Hayes_MD's amazing HRCT schema. I have been using it all during my pulm consult rotation.

Okay, back to UC: diagnosis is exclusion, but bronchoscopy can help rule out other causes:

▶️Rule out infections, malignancy, and sulfasalazine related disease
▶️PFT: will often present with obstruction or a mixed picture
▶️BAL/Biopsies: lymphocytosis and bronchiolitis

Management: really from case reports mostly, but use immunosuppressants:

▶️High Dose Corticosteroids
▶️anti-TNF (infliximab, adalimumab, etanercept)
▶️Steroid Sparing: Azathioprine, Myocphenolate Mofetil

What may be bad: Colectomy actually has been shown to worsen/trigger this!

Complications:
As stated before, a patient may also have bronchiectasis on top of bronchiolitis (more common conditions being more common). Look for treating + diagnosing the colonization by your common bronchiectasis related bugs before immunosuppressants are thrown on.

Summary

Ulcerative Colitis can rarely lead to inflammation of the bronchioles, often post-colectomy. This will present with tree-in-bud and centrilobular ground-glass opacities on HRCT. It is a dx of exclusion, and tx is with immunosuppression.

References
journal.chestnet.org/article/S0012-…

ncbi.nlm.nih.gov/pmc/articles/P…

ncbi.nlm.nih.gov/pmc/articles/P…

pubs.rsna.org/doi/full/10.11…

Would love thoughts, corrections, and anything to add! @EmmGeezee @emily_fri @david_furfaro @CPSolvers et al.!

And of course future partners in ms4 pulm crit nerd crime @DavidBassilyDO @ranukasinniah @ASanchez_PS and more