Internal Medicine Exam Rheumatology and Orthopedics 5

Question 1

A 60-year-old man on allopurinol develops a severe desquamating rash with mucous membrane involvement. Which HLA allele is strongly associated with this severe drug reaction?

Accepted Answer

HLA-B*58:01

Answer

HLA-B*58:01 is strongly associated with allopurinol-induced Stevens-Johnson syndrome and toxic epidermal necrolysis, particularly in Asian populations.

Question 2

A 55-year-old woman with RA develops leg ulcers, splenomegaly, and neutropenia. What is the most likely diagnosis?

Accepted Answer

Felty's syndrome

Answer

Felty's syndrome is the triad of rheumatoid arthritis, splenomegaly, and neutropenia, associated with severe seropositive RA.

Question 3

A 40-year-old man develops severe low back pain radiating to the buttocks, alternating sides, worse in the morning and improving with exercise. MRI shows sacroiliac joint edema. Which HLA type is most commonly associated?

Accepted Answer

HLA-B27

Answer

HLA-B27 is present in approximately 90% of patients with ankylosing spondylitis and is associated with all seronegative spondyloarthropathies.

Question 4

A patient with polymyositis has elevated CK, muscle weakness, and is started on prednisone. Two months later the CK normalizes but weakness worsens. What should be suspected?

Accepted Answer

Steroid myopathy

Answer

Steroid myopathy causes worsening weakness despite normalized CK, presenting a diagnostic dilemma; it is proximal, non-inflammatory, and improves with steroid dose reduction.

Question 5

A 65-year-old woman presents with shoulder and hip girdle pain and stiffness lasting >45 minutes in the morning, ESR of 85 mm/hr, and rapid response to low-dose prednisone. What is the diagnosis?

Accepted Answer

Polymyalgia rheumatica

Answer

Polymyalgia rheumatica presents with bilateral shoulder and hip girdle stiffness, markedly elevated ESR, and dramatic response to low-dose prednisone (15-20 mg/day).

Internal Medicine Exam Practice Test

Internal Medicine Exam Practice Test

Internal Medicine Exam Rheumatology and Orthopedics 5