🦴 Section 719.2 · Transient Monoarticular Synovitis (Toxic Synovitis)

Nelson Textbook of Pediatrics 22nd Edition | Transient synovitis: most common cause of hip pain in children ages 3-8 years. Reactive arthritis following viral illness (URI 7-14 days prior). Presentation: acute limp, groin/thigh/knee pain, low-grade fever or afebrile, able to bear weight (antalgic gait). Diagnosis of exclusion. Labs: ESR/CRP normal or mildly elevated. Ultrasound: small joint effusion. Must rule out septic arthritis — hip aspiration if fever >38.5°, refusal to bear weight, ESR >40, CRP >2, ill-appearing. Treatment: observation, NSAIDs, activity restriction. Resolves in 5-7 days.

🌐 paeds.online — Pediatric Learning Platform

📋 30 Clinical Scenarios — Transient Synovitis (Toxic Synovitis)

📇 High‑Yield Review Cards

🩺 Clinical Recognition: Transient Synovitis

Select a presentation to review diagnostic clues and management per Nelson 719.2.

📋 Stepwise Management of Transient Synovitis

🔑 Key Principles — Nelson Section 719.2
• Definition: Self-limited reactive arthritis of the hip, most common cause of hip pain in children 3-8 years.
• Etiology: Post-viral (upper respiratory infection 7-14 days prior).
• Presentation: Acute limp, groin/thigh/knee pain, low-grade fever (≤38°C) or afebrile. Child can bear weight (antalgic gait). Hip held in flexion, abduction, external rotation if significant effusion.
• Labs: WBC normal, ESR <20 mm/hr, CRP normal or ≤2 mg/dL (mild elevation possible).
• Imaging: Ultrasound shows small joint effusion. Radiographs normal.
• Treatment: Observation, NSAIDs, activity restriction. Resolves in 5-7 days.
• Critical distinction: Must rule out septic arthritis (surgical emergency).

    ⚡ Reflex Prompts — Clinical Decisions

    📖 Summary: Transient Synovitis (Nelson 719.2)