Differential diagnosis — Flashcards

Flashcard 321: Which cause of genital ulceration presents with painful vesicles on an erythematous base?_____

Answer: HSV

Flashcard 322: The _____ test helps distinguish GI mucosal damage from other causes of malabsorption (e.g. lactose intolerance)

Answer: D-xylose absorption

Flashcard 323: The Schilling test is useful in determining the etiology of vitamin _____ deficiency

Answer: B12

Flashcard 324: What is the appearance uric acid kidney stones on X-ray? _____

Answer: Radiolucent

Flashcard 325: Ischemic colitis may present with the '_____' sign on imaging due to mucosal edema/hemorrhage

Answer: thumbprint

Flashcard 326: _____ incontinence is due to incomplete emptying, due to detrusor underactivity or outlet obstruction

Answer: Overflow

Flashcard 327: A positive _____ sign is when minor pressure induces skin separation

Answer: Nikolsky

Flashcard 328: What is the most common cause of new-onset seizures in adults aged 35–65?

Answer: Brain tumor

Extra: Common causes of seizures by age: - **Children**: Febrile (most common), genetic, infection, trauma, congenital. - **Young adults (18–35)**: Trauma, alcohol withdrawal, illicit drugs. - **Adults (35–65)**: Brain tumor, stroke, trauma. - **Elderly (>65)**: Stroke (most common), tumor, trauma, metabolic.

Flashcard 329: What dermatologic lesion is a vesicle containing pus?_____

Answer: Pustule

Flashcard 330: What is the urine Na+ (mEq/L) in postrenal azotemia?

Answer: > 40 mEq/L

Extra: In **postrenal azotemia** (obstructive uropathy), tubular damage typically leads to an inability to reabsorb sodium, resulting in a **Urine Na+ > 40 mEq/L** and a FENa > 2%. **Note:** In the very early phase of obstruction (< 24 hours), tubular function may be temporarily preserved, mimicking prerenal azotemia (Urine Na+ < 20 mEq/L, FENa < 1%).