September Week 4: Septic vs. Reactive Arthritis

Recommended Reading: 

• Index of Suspicion, Pediatrics in Review, May 2002; 23: 179 – 185. CASE #4
• Approach to Acute Limb Pain in Childhood. Shirley M. L. Tse, MD, Ronald M. Laxer, MD Pediatrics in Review. 2006;27:170-180

Case 1
A 12 year old obese Black male presents with a 4 month history of left hip pain. He presents with a limp, and on exam, his left hip abducts and externally rotates on flexion. 

• What is your diagnosis? 
• How do you make the diagnosis? 
• How do you manage this in your clinic? 
• What is the treatment?

Case 2
A 3 year old female presents with refusal to bear weight on her right leg. She has a history of being irritable over the past week, and she has been running a fever of up to 39.1 C. On exam, she is febrile and ill-appearing. She refuses to bear any weight on her right leg, and she resists even gentle passive movement of her right hip. Her WBC are 14,000 and her ESR is 90. 

• What is the most likely diagnosis? 
• How do bacteria typically reach the joint? 
• What are the most common offending pathogens? 
• What are the commonly occurring sequelae? 
• How do you make the diagnosis? What studies are helpful? What is the management? 
• What if the girl allowed gentle hip motion, but has pain when the hip is flexed, abducted and externally rotated with pressure applied to the bent knee and opposite hip?

Case 3 
A 5 year old white male presents with a limp, as well as left thigh and knee pain. His symptoms have been intermittent over the past 2 months but they are now resolving. He was seen 6 weeks ago for these symptoms, but the xrays were completely normal. On exam, pt. is afebrile and in no acute distress. His knee and thigh are nontender to palpation or motion, but his symptoms are reproducible with left hip motion. 

• What is the typical age group affected with Leg-Calve-Perthes disease? 
• What is the male:female ratio? What racial group is typically spared? 
• What imaging would you obtain? What is the treatment?

Case 4
A 17 year old male presents to your office with dysuria and penile discharge. He denies fever or rashes but does complain of some lower back pain over last 2 days. He is sexually active and uses condoms “most of the time.” On physical exam, he is afebrile, with mildly injected sclera and some tenderness at lower lumbar area, but no CVA tenderness. He has no scrotal tenderness but scant yellow discharge from the urethra.

• What is your differential diagnosis? What organism is most likely? 
• What is your treatment? 
• If the patient had presented with only joint pain and swelling and skin pustules, what diagnosis would be more likely and how is the diagnosis confirmed?