STEP3 Exam Questions and Answers | Exam-Dumps (Page: 5)

QUESTION: 21

A28-year-old male, well known to your clinic, presents for management of swelling, pain, and tenderness that has developed in his left ankle and right knee. It has persisted for 1 month. Your patient reports that he developed severe diarrhea after a picnic 1 month prior to the onset of his arthritis. During the interval between the diarrhea and onset of arthritis, he developed a "pink eye" that lasted for 4 days. He denies any symptoms of back pain or stiffness. You remember that he was treated with ceftriaxone and doxycycline for gonorrhea 2 years ago, which he acquired from sexual activity with multiple partners. Since that time, he has been in a monogamous relationship with his wife and has not had any genitourinary symptoms. He promises that he has been faithful to his wife and has not engaged in unprotected sexual activity outside his marriage. His physical examination is notable for a swollen left ankle, swollen right knee, and the absence of penile discharge or any skin lesions. The patient's symptoms do not respond to your initial therapeutic management. You suspect that his condition is refractory to treatment. Which of the following should you consider at this time?

He may have human immunodeficiency virus (HIV) infection and should be tested.
His condition will require high doses of prednisone (60 mg daily) for adequate control.
His joints are obviously not infected and should be directly injected with corticosteroids.
He must have a disseminated bacterial infection that will require IV antibiotics.
He is resistant to indomethacin, so the dose should be doubled to 400 mg daily.

Answer(s): A

Explanation:

Reactive arthritis consists of a triad of nonspecific urethritis, conjunctivitis, and asymmetric arthritis, usually involving the large joints of the lower extremities. Genitourinary causes of reactive arthritis include Chlamydia or Ureaplasma. GI infections due to Salmonella, Shigella, Yersinia, Klebsiella, and Campylobacter can also cause reactive arthritis. Gout attacks are typically monoarticular and begin abruptly with the affected joint being exquisitely painful, warm, red, and swollen. These attacks often spontaneously resolve in 310 days. While the symptoms from pseudogout may mimic those of gout, they tend to be less painful and take longer to reach peak intensity. Gonococcal arthritis is seen more often in females, is associated with migratory arthralgia, tends to favor the upper limbs and knees and may be associated with cutaneous lesions (pustules). The absence of attacks and joint distribution makes gout and pseudogout less likely. The history of conjunctivitis and association with diarrhea makes the diagnosis of reactive arthritis more likely than resistant gonococcal arthritis. His clinical symptoms do not suggest ankylosing spondylitis, although if he was HLA-B27 positive he would be at increased risk of developing spondylitis. This patient has the classic symptoms and exposure risk (GI infection) to suggest reactive arthritis. For the articular symptoms, reduction of inflammation and restoration of function can be achieved with nonsteroidal antiinflammatories alone. A sufficient number of patients with reactive arthritis will not be HLA-B27 positive, thus rendering this test useless as a screening test. However, it may be useful when the clinical picture is incomplete (such as absence of antecedent infection or lack of extraarticular features). Once an antecedent infection has triggered reactive arthritis, it is unlikely that antibiotics will affect the course of the illness (except in the case of chlamydiaassociated urogenital disease where a trial of prolonged antibiotic therapy may be reasonable).

Systemic corticosteroids are usually ineffective in reactive arthritis, but may be tried for resistant disease or conditions such as AIDS in which cytotoxic therapy is contraindicated. Given the absence of skin lesions, penile discharge, or urogenital symptoms, one would be hard-pressed to challenge the patient's statement that he has not engaged in unprotected sex at the risk of jeopardizing the physicianpatient relationship. Reactive arthritis may be the first manifestation of HIV infection. Therefore, HIV antibody status should be determined when the appropriate risk factors and/or clinical features are present. As mentioned previously, systemic steroids are usually ineffective for reactive arthritis and, with the possibility of joint infection, would necessitate ruling out infection by arthrocentesis of the affected joints. Joint infection cannot be ruled out based on his presentation, and joint sepsis must be excluded prior to corticosteroid injection. The clinical presentation is classic for reactive arthritis, and the absence of systemic symptoms makes the likelihood of disseminated bacterial infection low. Indomethacin, at a dose of 150200 mg/day, is the prototypic NSAID medication for treatment of reactive arthritis. Doses higher than this are associated with significant GI complications and do not improve efficacy in a patient resistant to the standard dose. In the event that the patient does not respond to 200 mg of indomethacin or alternative NSAIDs, disease- modifying antirheumatic drugs (DMARD) such as methotrexate, azathioprine, or sulfasalazine may be used, provided that HIV test results are negative, as these immunosuppressants have been reported to precipitate the onset of AIDS in HIV-positive patients.

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QUESTION: 22

A 42-year-old man presents to your clinic with a 1-week history of pain and inflammation involving his right first metatarsophalangeal (MTP) joint. He describes the pain as sudden in onset and worse at night. He denies experiencing any fever or traumatic injury to the joint and states that he has never had this type of pain before. He denies any chronic medical conditions, any prior surgery, and any current medication use. Besides an erythematous and exquisitely tender right first MTP joint, the remainder of his physical examination is unremarkable.

Which of the following is true of the patient's condition?

It commonly presents in premenopausal women.
It commonly presents as a monoarticular arthritis.
Episodes of pain and inflammation become more frequent but resolve more quickly as the disease progresses.
The presence of tophi is a common early finding.
A blood test is the diagnostic gold standard.

Answer(s): B

Explanation:

This patient's presentation is consistent with gout. Aspiration of his first MTP joint is likely to reveal the presence of needle-shaped, negatively birefringent crystals. Rhomboid-shaped, positively birefringent crystals are characteristic of calcium pyrophosphate deposition disease, or pseudogout, with the knee being the joint most commonly affected. Nonbirefringent crystals are found in hydroxyapatite crystal deposition disease. The synovial fluid from joints affected by gout typically show evidence of inflammation in the form of leukocytosis with a predominance of polymorphonuclear neutrophils. The presence of bacteria in synovial fluid is characteristic of infection rather than gout, although gout and infectious arthritis may coexist. (Cecil Textbook of Medicine, pp. 17031708) Acute gouty arthritis usually presents in a monoarticular or oligoarticular distribution, with the first MTP joint most commonly affected. The diagnostic gold standard is detection of urate crystals within the synovial fluid of affected joints. It most commonly affects adult men with a peak incidence in the fifth decade of life. While patients with gout typically also have hyperuricemia, only a small fraction of the people with hyperuricemia actually have or will develop gout.

Tophi are primarily seen in patients with long-standing hyperuricemia and is considered a finding of chronic gouty arthritis. As the disease progresses, acute attacks become more frequent and last longer if left untreated. Indomethacin inhibits the prostaglandin synthesis that facilitates the inflammation of acute gout and inhibits the phagocytosis of urate crystals by leukocytes. This inhibits the cell lysis and release of cytotoxic factors that initiate the inflammatory cascade. Allopurinol (an inhibitor of urate synthesis) and probenecid and sulfinpyrazone (promoters of urate excretion) are useful for preventing gout but are not effective during an acute gout attack. Aspirin is inappropriate in the treatment of gout since it can inhibit urate elimination and, therefore, increase hyperuricemia.

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QUESTION: 23

A54-year-old Asian female with no significant medical history presents with frontal headache, eye pain, nausea, and vomiting. Her abdominal examination shows mild diffuse tenderness but no rebound or guarding. Her mucous membranes are dry. Her vision is blurry in both eyes, her eyes are injected but her extraocular muscles are intact. Her pupils are mid-dilated and fixed

Which of the following is the most likely diagnosis?

diabetic ketoacidosis (DKA)
appendicitis
angle closure glaucoma
perforated colon due to inflammatory bowel disease (IBD)
cerebellar malignancy

Answer(s): C

Explanation:

The presence of headache, eye pain, nausea, and vomiting should prompt the consideration of the diagnosis of acute angle closure glaucoma. This is a rare but serious condition in which the aqueous outflow is obstructed, and the intraocular pressure abruptly rises. Susceptible eyes have a narrow anterior chamber and when the pupil becomes dilated, the peripheral iris blocks the outflow via the anterior chamber angle. Edema of the cornea occurs, resulting in cloudiness on examination. Diagnosis is made by measuring the intraocular pressure during an acute attack. Treatment includes medications to induce miosis in an effort to relieve the blockage or, if that fails, surgical intervention. In some patients, the headache or GI symptoms can overshadow the ocular symptoms, resulting in a delay in diagnosis and unnecessary workup for other conditions. In this case, the lack of findings on abdominal examination makes appendicitis or perforated
bowel unlikely. DKA can present with primary GI symptoms, but would not explain the ocular symptoms. Similarly, cerebellar or other brain tumors may cause headache, nausea, and vomiting, but would not be causes of a painful, red eye.

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QUESTION: 24

A 64-year-old male with a history of hypertension and tobacco abuse presents for follow-up after a routine physical during which he was found to have 45 red blood cells (RBCs) per high-power field (HPF) on a screening urinalysis. The urinalysis was negative for leukocytes, nitrites, epithelial cells, and ketones. The patient denies any complaints and the review of systems is essentially negative.

What would be your initial approach in the workup of this patient with asymptomatic microscopic hematuria?

check PSA and urine culture
CT scan with and without contrast of the abdomen and pelvis
intravenous pyelography (IVP)
observation and reassurance as patient is asymptomatic
repeat urinalysis

Answer(s): E

Explanation:

Asymptomatic microscopic hematuria is defined by the American Urological Association as three or more RBCs per high power field on urinary sediment from two out of three properly collected urinalyses. A proper sample can be a midstream clean-catch specimen. The urine dipstick is roughly 91100% sensitive and 65- 99% specific for detection of RBCs, Hgb, and myoglobin. Urine dipstick is not reliable in distinguishing myoglobin from Hgb or RBCs. Therefore, urinalysis with microscopy should be ordered to assess the number of RBCs per high power field. Microscopic hematuria is usually an incidental finding but deserves a thorough workup, as 10% can be due to malignancy. The initial approach is to repeat the urinalysis to rule out infection. If the urinalysis suggests infection by the presence of WBCs or nitrites, a culture should be ordered and the patient treated appropriately. If RBCs are present without any leukocytes, nitrites, or epithelial cells on the repeated urinalysis, a proper workup should ensue. After history and physical are done to rule out risk factors, comorbidities, or other etiologies to account for the hematuria, one must look to diagnostic tests. A serum creatinine is useful to assess for renal insufficiency. During the course of the workup, if the urinalysis and serum creatinine suggest a glomerular etiology (casts, elevated creatinine, dysmorphic RBCs) a renal consultation and possible renal biopsy may be warranted. Evaluation of the upper tract with either an IVP or CT scan of the abdomen/pelvis with and without contrast should be ordered to rule out renal cell carcinoma, nephrolithiasis, or aneurysms. Next, the lower tract should be visualized by cystoscopy and washings sent for cytology. If all the above workup is negative, the patient can be reassured and followed with a repeat urinalysis in 6 months.

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QUESTION: 25

A 64-year-old male with a history of hypertension and tobacco abuse presents for follow-up after a routine physical during which he was found to have 45 red blood cells (RBCs) per high-power field (HPF) on a screening urinalysis. The urinalysis was negative for leukocytes, nitrites, epithelial cells, and ketones. The patient denies any complaints and the review of systems is essentially negative .

change of antihypertensive agent and recommendation to patient to discontinue smoking
image the upper and lower urinary tracts
antibiotics for 1 month
expectant management with follow-up urinalysis in 6 months E. nephrology consultation

Answer(s): B

Explanation:

Asymptomatic microscopic hematuria is defined by the American Urological Association as three or more RBCs per high power field on urinary sediment from two out of three properly collected urinalyses. A proper sample can be a midstream clean-catch specimen. The urine dipstick is roughly 91100% sensitive and 65- 99% specific for detection of RBCs, Hgb, and myoglobin. Urine dipstick is not reliable in distinguishing myoglobin from Hgb or RBCs. Therefore, urinalysis with microscopy should be ordered to assess the number of RBCs per high power field. Microscopic hematuria is usually an incidental finding but deserves a thorough workup, as 10% can be due to malignancy. The initial approach is to repeat the urinalysis to rule out infection. If the urinalysis suggests infection by the presence of WBCs or nitrites, a culture should be ordered and the patient treated appropriately. If RBCs are present without any leukocytes, nitrites, or epithelial cells on the repeated urinalysis, a proper workup should ensue. After history and physical are done to rule out risk factors, comorbidities, or other etiologies to account for the hematuria, one must look to diagnostic tests. A serum creatinine is useful to assess for renal insufficiency. During the course of the workup, if the urinalysis and serum creatinine suggest a glomerular etiology (casts, elevated creatinine, dysmorphic RBCs) a renal consultation and possible renal biopsy may be warranted. Evaluation of the upper tract with either an IVP or CT scan of the abdomen/pelvis with and without contrast should be ordered to rule out renal cell carcinoma, nephrolithiasis, or aneurysms. Next, the lower tract should be visualized by cystoscopy and washings sent for cytology. If all the above workup is negative, the patient can be reassured and followed with a repeat urinalysis in 6 months.

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USMLE STEP3 Exam (page: 5) USMLE Step3 Updated on: 15-Feb-2026

QUESTION: 21

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QUESTION: 22

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QUESTION: 23

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QUESTION: 24

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QUESTION: 25

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USMLE STEP3 Exam (page: 5)
USMLE Step3
Updated on: 15-Feb-2026