Differential Diagnosis for Intermittent Limp in a 2-Year-Old Child

Single Most Likely Diagnosis

• Transient Synovitis: This condition is the most common cause of acute hip pain and limp in children, often following a viral infection. It's characterized by inflammation of the synovial membrane of the hip joint, leading to pain and limp.

Other Likely Diagnoses

• Toddler's Fracture: A small fracture in one of the long bones of the leg, common in toddlers who are learning to walk. It can cause intermittent pain and limp.
• Developmental Dysplasia of the Hip (DDH): Although more commonly diagnosed at birth or during infancy, some cases might not be apparent until the child starts walking, presenting with a limp.
• Septic Arthritis: An infection within a joint, which can cause severe pain, swelling, and limp. It's a medical emergency requiring prompt treatment.

Do Not Miss Diagnoses

• Slipped Capital Femoral Epiphysis (SCFE): A condition where the ball at the upper end of the femur (thigh bone) slips out of place. It's more common in older children but can occur in younger ones, especially if they are overweight. Early diagnosis is crucial to prevent long-term damage.
• Bone Tumors (e.g., Osteosarcoma, Ewing's Sarcoma): Although rare, these conditions can present with pain and limp. Early detection significantly improves prognosis.
• Child Abuse: Non-accidental trauma can cause fractures or other injuries leading to limp. It's essential to consider this possibility, especially if the history provided does not match the injury or if there are other signs of abuse.

Rare Diagnoses

• Legg-Calve-Perthes Disease: A rare condition where the blood supply to the ball of the hip joint is disrupted, leading to the ball's death and collapse. It typically affects children between 4 to 8 years old but can occur in younger children.
• Juvenile Idiopathic Arthritis (JIA): A chronic autoimmune disease that can cause joint pain, swelling, and limp. It's less common in very young children but should be considered if other symptoms like fever or rash are present.
• Neurological Conditions (e.g., Cerebral Palsy, Muscular Dystrophy): These conditions can cause gait abnormalities and limp due to muscle weakness or spasticity. They are usually diagnosed based on a combination of clinical findings and diagnostic tests.