Lymphangitis is an infection of lymph vessels, while being a complication of some bacterial infections.

-Key words in vignette is "red streak extending to elbow".

Look at this picture: https://www.jpeds.com/article/S0022-3476(13)00037-1/fulltext.

The form is made because the streak follows the shape of the lymph node. Very noticeable once you see the image.

-Superficial thromphlebitis can't be the answer because it is generally caused by clotting in woman over 40 or 6 months post partum.

Remember the question asks "most likely" but many of some of these choices can definitely be in the differential diagnosis.

SLE like other autoimmune diseases, may improve or worsen, or can present for the first time during pregnancy. Obstretic complications related to SLE: -Maternal (preeclampsia), - -Fetal (neonatal lupus, intrauterine fetal demise)-

-Fetal findings: -Cardiac (fetal AV block) that occurs due to maternal autoantibodies binding to fetal cardiac cells. Causes irreversible injury to AV nose. The ventricular heart rate will determine the baseline fetal heart rate and will present with fetal bradycardia (less than 110 beats per minute). - -If the heart block is prolonged, hydrops fetalis can occur.

(https://www.jpedhc.org/article/S0891-5245(13)00232-0/fulltext) Uworld Question ID (12531)

The majority of infants with CF and MI, whether simple or complex, have pancreatic insufficiency (PI). Confirmation of PI is most efficiently and effectively done by obtaining a fecal elastase. However, the fecal elastase sample should be collected from rectally delivered, formed stools and not from an enterostomy. Watery stools from either an enterostomy or rectally delivered can result in falsely low fecal elastase values. Therefore, in infants with MI and an enterostomy, PI should be assumed and fecal elastase collected at a later date after the gastrointestinal tract is back in continuity and stools are at least of a pasty consistency to confirm diagnosis. Once the infant is able to take a minimal amount of formula or breastmilk by mouth or feeding tube, PERT should be initiated at 2000–4000 lipase units per 120 mL of formula [[37]]. PERT contains lipase to digest to lipids, amylase to digest carbohydrates, and protease

https://www.cysticfibrosisjournal.com/article/S1569-1993(17)30809-3/fulltext#secst0030

you dont see a cherry rod spot on fundoscopic exam picture - indication for fluorescein angiography to CONFIRM the diagnosis. they need to ask a different question if they want us to pick doppler. nbme always wins=(

Decubitus ulcer is a pressure sore that could be anywhere on the body, and in this case is on the head because the baby can't move.

Ecthyma gangrenosum is an infection usually seen in patients who are critically ill and immunocompromised. The characteristic lesions of ecthyma gangrenosum are haemorrhagic (bloody) pustules that evolve into necrotic (black) ulcers, which doesn't really fit the description here.

Kerion is an abscess caused by a fungal infection, and likely wouldn't be ulcerative

Recluse spider bite would have more severe systemic symptoms in a child (weakness, fever, joint pain, hemolytic anemia, thrombocytopenia, organ failure, disseminated intravascular coagulation, seizures, or death) and you would see puncture wounds.

I didn't think atypical TB or scabies made sense so I didn't go into those.

Even though most small cell lung cancer shows up in late stages, and only 2% of people diagnosed are alive after 2 years, people still frequently get treatment. Usually this is both chemo and radiation, but the chemo comes first to shrink the cancer so you don't have to radiate as large an area. Chemo + radiation is also sometimes used as paliation. (https://www.ncbi.nlm.nih.gov/books/NBK482458/)

"Nerve conduction studies (NCS) and needle electromyography (EMG) are valuable for confirming the diagnosis of GBS and for providing some information regarding prognosis. In addition, electrodiagnostic studies are useful in classifying the main variants of GBS as demyelinating (eg, acute inflammatory demyelinating polyneuropathy) or axonal (eg, acute motor axonal neuropathy" UTD

Nobody has mentioned this but I think another thing that helps with this answer is that the boy was infected with all these that he was immunized for. A 12 month old should've had immunizations for H. flu, and Strep pneumo, yet he was still getting sick. This makes me think he isnt making proper antibodies --> therefore a B cell issue

The patient has SCLC (histo description: uniform, small round cells w/darkly staining nuclei). This type is unresectable (only rare cases of small tumors w/o node involvement), responds to chemo and radiation initially, given more so as palliative care.

High Calcium and low phosphorus --> probably has high PTH.

Vitamin D - leads to absorption of both calcium and phosphorus, so you would have high Ca and Ph. PTH - differentiates between Ca and Ph, it increases Calcium in the body and decreases phosphorus in the body.

BMI ≥40 --> Gastric Bypass candidate. BMI ≥35 + comorbidity --> Gastric Bypass candidate.

She has already tried weight loss without success. Plus she is a compliant patient (diet, insulin regimen, and daily glucose monitoring)

Everyone has a story and a struggle, and weight is not dependent just on our effort or workout regimen. Genetics, microbiome, and many other factors play a role. Let's not judge these patients but help them!

I thought I heard in a Divine podcast that if the labs showed pretty clear gallstone pancreatitis you could just skip the US and go right to ERCP. Guess not.

NPPV is approved for hospice patients for palliative reasons.

This patient is struggling to breathe, which is probably causing her some degree of suffering.

NPPV is non-invasive, and could alleviate her pain while not being a curative measure.

UTD:

Stabilization - Circulation

A child with exertional heat stroke may require 60 mL/kg or more of normal saline.

Rapid cooling

For children receiving treatment for heat stroke in the hospital, we suggest evaporative cooling rather than cold-water immersion. Evaporative cooling is preferred for hospital treatment of heat stroke in children because it does not interfere with efforts to maintain monitoring and ongoing resuscitation in unstable patients. Cold-water immersion is associated with significant discomfort, shivering, agitation, and combativeness; and is not clearly more efficacious for rapid cooling in the pediatric population. When evaporative cooling is not available, cold immersion is suggested.

https://www.uptodate.com/contents/heat-stroke-in-children

TL;DR

• Everyone needs fluids (and those should probably be administered ASAP)
• Cold-water immersion is not preferred

Why echo and not angiography?

From UTD:

Aortic disease

As recommended in the 2010 American College of Cardiology/American Heart Association/American Association for Thoracic Surgery thoracic aorta guidelines, echocardiography is recommended at initial diagnosis and at six months to assess the aortic root and ascending aorta in patients with MFS

Approach to diagnosis of MFS

MFS is most commonly diagnosed using the 2010 revised Ghent Criteria. These are based on the presence or absence of family history, physical examination, imaging of the aorta, and genetic testing in some cases.

The revised Ghent nosology puts greater weight on aortic root dilatation/dissection and ectopia lentis as the cardinal clinical features of MFS and on testing for mutations in FBN1. For the aortic criteria, aortic root Z score calculators are available for children and adults.

In the absence of family history of MFS

For individuals without a family history of MFS, the presence of one of any of the following criteria is diagnostic for MFS:

• Aortic criterion (aortic diameter Z ≥2 or aortic root dissection) and ectopia lentis.

• Aortic criterion (aortic diameter Z ≥2 or aortic root dissection) and a causal FBN1 mutation.

• Aortic criterion (aortic diameter Z ≥2 or aortic root dissection) and a systemic score ≥7.

• Ectopia lentis and a causal FBN1 mutation that has been identified in an individual with aortic aneurysm.

https://www.uptodate.com/contents/genetics-clinical-features-and-diagnosis-of-marfan-syndrome-and-related-disorders

https://pubmed.ncbi.nlm.nih.gov/20591885/

TL;DR Echo for aortic diameter

What the hell is going on here? Still no answer that makes sense. We have:

• "Poor air movement, especially on the LEFT"
• What looks like a RIGHT tension pneumothorax on CXR
• Shock and stupor ensue...
• Oh, and also hypovolemic shock and maybe a weirdly shifted PMI

Put it all together: RIGHT tension pneumothorax

But why the hell are breath sounds decreased on the LEFT? That alone made me switch to some crazy heart crushing atelectasis answer. I honestly thing the R/L mixup may be a typo because without that the question is simple.