USMLE Daily Rounds

USMLE questions, clinical reasoning & high-yield concepts, every day. 🩺

Think like a doctor. Answer like an examiner.

[USMLE Daily Rounds @USMLERounds]

🚨 A 68-year-old man with hypertension and CKD is admitted for community-acquired pneumonia.

On hospital day 3 he develops acute pleuritic chest pain and dyspnea.

Vitals: HR 118, BP 138/82, RR 26, O₂ sat 92% on 4L NC.

Labs:
* D-dimer markedly elevated
* Troponin mildly elevated
* BNP elevated
* Cr 2.8 mg/dL (baseline 1.9)

=> What is the most likely diagnosis?
=> What's the appropriate next step?

[USMLE Daily Rounds @USMLERounds]

🫀 Boot-shaped heart on CXR = ?

What are the 4 classic features?

Drop your answers.

[USMLE Daily Rounds @USMLERounds]

A 32-year-old pregnant female at 28 weeks gestation comes in for routine prenatal visit. She has type 1 diabetes mellitus.

Her self-monitoring blood glucose logs show:
* Fasting: 90 – 95 mg/dL
* 1 hour postprandial: 130 – 140 mg/dL

However, her lab HbA1c is reported as 4.8%.

The physician also notes she has homozygous sickle cell anemia (HbSS).

Which of the following laboratory markers would provide the most accurate assessment of her glycemic control over the past 2 – 3 weeks?

A) Fasting plasma glucose
B) Fructosamine
C) HbA1c repeat test
D) OGTT
E) Urine ketones

Explain your answer in the comment section.

[USMLE Daily Rounds @USMLERounds]

Why not the others?

A. Adenosine deaminase => SCID

B. Glucose-6-phosphatase => Von Gierke disease

D. Xanthine oxidase deficiency => Xanthinuria (low uric acid, not gout)

[USMLE Daily Rounds @USMLERounds]

Answer: C. HGPRT

=> The combination of developmental delay, self-mutilation (lip/finger biting), hyperuricemia, and gout is classic for Lesch-Nyhan syndrome.

=> Lesch-Nyhan syndrome is caused by deficiency of Hypoxanthine-Guanine Phosphoribosyltransferase (HGPRT), a purine salvage enzyme.

=> Loss of HGPRT leads to increased purine degradation and excess uric acid production, causing gout and neurologic manifestations.

[USMLE Daily Rounds @USMLERounds]

Answer: B. Severe Combined Immunodeficiency (SCID)

=> The thymus is the site of T-cell maturation, so an absent thymic shadow suggests a profound T-cell deficiency.

=> SCID is characterized by severe defects in both T-cell and B-cell function, leading to severe lymphopenia and recurrent infections early in life.

=> On chest X-ray, infants with SCID often have an absent thymic shadow due to lack of normal thymic development.

[USMLE Daily Rounds @USMLERounds]

An absent thymic shadow on a newborn X-ray combined with severe lymphopenia indicates which defect?

A. Bruton agammaglobulinemia
B. Severe combined immunodeficiency (SCID)
C. Chronic granulomatous disease
D. C5-C9 complement deficiency

[USMLE Daily Rounds @USMLERounds]

@_uakbar ✅ Correct

Diffuse concave ST elevation + PR depression = pericarditis until proven otherwise.

What’s the most common cause of pericarditis in a young healthy patient vs an older one?

[USMLE Daily Rounds @USMLERounds]

Which condition characteristically presents with diffuse ST-segment elevations and PR-segment depressions on ECG?

A. Acute myocardial infarction
B. Acute pericarditis
C. Pulmonary embolism
D. Dilated cardiomyopathy

[USMLE Daily Rounds @USMLERounds]

@medicinedr18 ✅ Correct

Diffuse concave ST elevation + PR depression = pericarditis until proven otherwise.

What drug is the first line of treatment?

[USMLE Daily Rounds @USMLERounds]

@ajlkfad2333 ✅ Correct

Diffuse concave ST elevation + PR depression = pericarditis until proven otherwise.

What’s one ECG finding that would make you worry about tamponade instead?

[USMLE Daily Rounds @USMLERounds]

@drpankajroyal In classic PCP, TMP-SMX is first-line.
Don’t forget steroids in hypoxic patients.

What would you switch to if allergic to sulfa?

[USMLE Daily Rounds @USMLERounds]

🚨 HIV patient, CD4 80.
Fever, dry cough, exertional dyspnea.
BAL silver stain shows disc-shaped cysts.

First-line treatment?

A. Azithromycin
B. Ganciclovir
C. Trimethoprim-sulfamethoxazole
D. Fluconazole

Answer With Reasons

[USMLE Daily Rounds @USMLERounds]

Never Forget;

SildenaFIVE = Phosphodiesterase-5

[USMLE Daily Rounds @USMLERounds]

@Clifford_oyo Yes... that's correct

[USMLE Daily Rounds @USMLERounds]

This positive Babinski sign.

It indicates an upper motor neuron (UMN) lesion, and it reflects loss of inhibitory control from higher brain centers.

[RxOfLife💉 @Chiragrx07]

1. LMN or UMN??
2. Why it's happening??

[USMLE Daily Rounds @USMLERounds]

@Chiragrx07 That's correct

[USMLE Daily Rounds @USMLERounds]

@Chiragrx07 Exactly right @Chiragrx07

In classic PCP, TMP-SMX is first-line.
Don’t forget steroids in hypoxic patients.

What would you switch to if allergic to sulfa?