General note: If you have a choice between acetaminophen and an NSAID for an acute injury, acetaminophen will always be the right choice. Most acute injuries are not inflammatory and acetaminophen is a lot safer without gastropathy or platelet inhibition. If you do use an NSAID, naproxen is the safest from a cardiovascular standpoint but carries the same gastrointestinal risks as other NSAIDs.
A 5-year-old boy presents with acute onset of left anterior thigh and hip pain that began 2 days ago with no known prior trauma. He reports that it initially "loosened-up" after he had been out of bed for a few hours but has become worse again by afternoon. His pain is exacerbated by weight bearing and active or passive range of motion (ROM). His mother notes that he had a cold 7 to 10 days ago, but has been asymptomatic until he complained of thigh pain two nights ago. She also notes that he has had a low-grade fever. He has no other significant constitutional symptoms and appears to be in some pain, but otherwise he appears well.
Question 12.1.1 Based on the information obtained thus far, which of the following is the most likely diagnosis?
C) Slipped capital femoral epiphysis (SCFE).
D) Legg–Calve–Perthes disease (LCPD).
E) Transient (toxic) synovitis.
Answer 12.1.1 The correct answer is "E." This presentation is classic for transient (toxic) synovitis. This is the most common cause of hip pain in children aged 3 to 10 years, with peak occurrence in ages 5 to 6 years. It is more commonly seen in boys (male:female ratio of 2–3:1) and is often preceded by a viral respiratory infection, although numerous studies have failed to demonstrate a specific viral or bacterial agent. Physical examination reveals a limp or refusal to walk and complaint of pain over the groin and/or proximal thigh. There is pain with ROM testing, especially during abduction. Most children will be afebrile with a temperature of ≤38°C.
Question 12.1.2 Appropriate diagnostic work-up might include which of the following?
B) Plain film radiographs.
C) Inflammatory markers including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).
D) CBC with differential.
Answer 12.1.2 The correct answer is "E." All of the above may be appropriate as transient synovitis is a ...