WBR0408

Author	[[PageAuthor::Mugilan Poongkunran M.B.B.S [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Primary Care Office
Sub Category	SubCategory::Musculoskeletal/Rheumatology
Prompt	[[Prompt::27 year old male presents to the office with several day history of low back pain. He says he has been having such pain for the past 4 months. His pain is more severe early morning and improves during the day and feels better on taking NSAID's. His past medical history is insignificant. He is a chronic smoker and alcoholic. He is sexually active and does not use condoms. Physical examinations shows hip joint tenderness with restriction of spine. Examination of the other joints are normal. Initial lumbosacral X-ray shows mild disease involving the sacroiliac joints. What is most appropriate plan to monitor the disease activity?]]
Answer A	AnswerA::Order MRI spine in 3 months
Answer A Explanation	[[AnswerAExp::Incorrect : The findings on MRI in a patient with ankylosing spondylitis is synovial enhancement. It is superior to CT in detection of cartilage, bone erosions, and subchondral bone changes. An increased T2 signal correlates with edema or vascularized fibrous tissue. MRI is not used to monitor disease activity until patient has cauda-equina syndrome.]]
Answer B	AnswerB::Order HLA B 27 in 3 months
Answer B Explanation	AnswerBExp::'''Incorrect''' : HLA B27 high levels at the start of the disease may indicate poor overall prognosis. But it is not used to monitor disease activity.
Answer C	AnswerC::Order RF and ANA levels in 3 months
Answer C Explanation	[[AnswerCExp::Incorrect : RF and ANA has roles mainly in rheumatoid arthritis and systemic lupus erythematosis but not in ankylosing spondylitis.]]
Answer D	AnswerD::Order ESR and C-reactive protein in 3months
Answer D Explanation	[[AnswerDExp::Correct : The erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) are useful for monitoring disease activity, if they are elevated at baseline of treatment. Elevated CRP levels are associated with increased risk of radiographic progression both in the sacroiliac joints and in the spine.]]
Answer E	AnswerE::Order CT spine in 3 months
Answer E Explanation	[[AnswerEExp::Incorrect : An option for more accurate and much earlier diagnosis of ankylosing spondylitis is tomography of the sacroiliac joints. Joint erosions, subchondral sclerosis, and bony ankylosis are better visualized on CT. They are not used to monitor disease activity.]]
Right Answer	RightAnswer::D
Explanation	[[Explanation::Ankylosing spondylitis typically presents in a young patient with chronic pain and stiffness in lower part of spine. In most paetients, ankylosing spondylitis is associated with iridocyclitis (anterior uveitis) causing eye pain and photophobia (increased sensitivity to light). Other common symptoms are recurring mouth ulcers (aphthae) and fatigue. A clinical examination and X-ray studies of the spine, which show characteristic spinal changes and sacroiliitis, are the major diagnostic tools for ankylosing spondylitis. The findings on X Ray are presence of subchondral erosions, sclerosis, proliferation on iliac side of SI joints and squaring of the vertebral body. X-ray and acute phase reactants are used to monitor disease activity in these patients. Educational Objective: References: ]]
Approved	Approved::Yes
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