If you’re preparing for the United States Medical Licensing Examination® (USMLE®) Step 3 exam, you might want to know which questions are most often missed by test-prep takers. Check out this example from Kaplan Medical, and read an expert explanation of the answer. Also check out all posts in this series.  

AMA Member Benefits PLUS

  • Headspace meditation & mindfulness app: Free for 2 years 
  • Kaplan: Save 30% on USMLE test prep 

The AMA selected Kaplan as a preferred provider to support you in reaching your goal of passing the USMLE® or COMLEX-USA®. AMA members can save 30% on access to additional study resources, such as Kaplan’s Qbank and High-yield courses. Learn more.

This month’s stumper

Your patient is extremely distressed at a worsening tightening of the skin developing around the face and hands. The patient also has epigastric pain radiating into the chest. There is no shortness of breath or hypertension. Chest x-ray is normal and BUN and creatinine are normal. Echocardiography shows a pulmonary artery pressure that is elevated. Pulmonary function testing is planned. The patient asks about her prognosis.

Which of the following represents the greatest difference between limited scleroderma (CREST syndrome) and diffuse systemic sclerosis?

A.  Anti-centromere antibodies.

B. ANA.

C. Raynaud's phenomenon.

D. Esophageal dysmotility.

E. Hand involvement.

Related Coverage

USMLE Step 3: Tips for balancing rotations with exam prep

 

 

 

 

 

 

 

The correct answer is A.

Kaplan Medical explains why

Anti-centromere antibodies are present in almost all patients with CREST syndrome (90%) but in virtually no patients (less than 5%) with diffuse systemic sclerosis (scleroderma).

Why the other answers are wrong

Choice B: The ANA is present in the majority of patients with both syndromes.

Choice C, D and E: Raynaud's phenomenon, esophageal dysmotility, and hand involvement known as sclerodactyly are present in both syndromes. Esophageal dysmotility manifests as gastroesophageal reflux disease in both patient groups.

Related coverage

Kaplan USMLE Step 3 prep: Man with type 1 diabetes found comatose

Tips to remember

Anti-centromere antibodies are present in CREST syndrome, but not in diffuse systemic sclerosis (scleroderma).

For more prep questions on USMLE Steps 1, 2 and 3, view other posts in this series.

Static Up
73
More about:
Featured Stories