How to elicit a medical history in a pediatric patient presenting with lower limb weakness?

History Taking in Children with Lower Limb Weakness

When evaluating a child with lower limb weakness, immediately determine if fever is present and whether the child can bear weight, as fever >101.3°F (38.5°C) combined with refusal to bear weight indicates septic arthritis requiring intervention within hours to prevent permanent joint damage. 1, 2, 3

Critical Red Flags to Identify First

Begin by assessing for life-threatening or limb-threatening conditions:

• Fever assessment: Document exact temperature, as fever >101.3°F (38.5°C) with inability to bear weight strongly suggests septic arthritis 1, 2, 3
• Weight-bearing status: Complete refusal to bear weight or move a joint is highly concerning for septic arthritis or fracture 1, 2
• Systemic toxicity: Ask about lethargy, irritability, poor feeding, or altered consciousness—these indicate serious infection requiring urgent evaluation 1, 2
• The "three As": In young children who cannot verbalize symptoms, assess for anxiety, agitation, and high analgesic requirements, which may indicate serious pathology 2

Essential History Components

Timing and Pattern of Weakness

• Onset: Acute (hours to days) versus chronic (weeks to months) 3, 4
• Progression: Stable, improving, or worsening symptoms 1, 2
• Duration: Document exact timeline of symptom development 2, 3

Pain Characteristics

• Presence and severity: Determine if weakness is accompanied by pain, as painless weakness suggests different etiologies than painful weakness 5, 3
• Location: Young children frequently mislocalize pain—hip pathology presents as knee pain in up to 30% of cases 5, 2
• Pattern: Constant versus intermittent, worse with activity or at rest 3

Trauma History

• Recent injury: Even minor trauma can cause occult fractures, particularly spiral tibial fractures in children under 4 years 1, 5
• Mechanism: Twisting injuries, falls, or direct blows 3
• Timing: Symptoms may appear days after injury 5

Functional Impact

• Gait pattern: Ask parents to describe how the child walks—limping, dragging leg, toe-walking, or complete inability to walk 3, 4
• Activity level: Changes in play, running, climbing stairs, or participation in sports 2, 3
• Bilateral versus unilateral: Determine if one or both legs are affected 2

Age-Specific Considerations

Infants and Toddlers (0-3 years)

• Developmental milestones: Ask if the child was previously walking normally and when weakness began 2
• Refusal to crawl or stand: May be the only sign in pre-verbal children 2
• Irritability with diaper changes: Suggests hip pathology 2

Older Children (>3 years)

• Ability to localize symptoms: Older children can better describe where weakness or pain is located 5, 2
• Sports participation: Recent increase in activity or specific sports injuries 6

Associated Symptoms

• Neurological symptoms: Headaches, vomiting, sensory changes, bowel/bladder dysfunction, or upper extremity involvement suggest spinal pathology 7
• Dental infections: Recurrent dental abscesses or maxillofacial cellulitis may indicate metabolic bone disease 6
• Bone pain and fatigue: Chronic symptoms suggesting metabolic or systemic disease 6
• Joint swelling or stiffness: Suggests inflammatory or rheumatic conditions 3

Past Medical and Family History

Medical Conditions

• Metabolic bone disease: History of rickets, hypophosphatemia, or vitamin D deficiency 6
• Neuromuscular disorders: Cerebral palsy, spina bifida, muscular dystrophy, or spinal muscular atrophy 6
• Systemic diseases: Inflammatory bowel disease, systemic lupus erythematosus, juvenile idiopathic arthritis 3
• Previous infections: Osteomyelitis, septic arthritis, or recent viral illnesses 3

Family History

• Genetic bone disorders: Family history of metabolic bone disease, skeletal dysplasias, or chromosomal abnormalities 6
• Neuromuscular conditions: Inherited muscle or nerve disorders 6

Growth and Development History

• Height and growth velocity: Poor growth may indicate metabolic bone disease 6
• Head circumference: In children <5 years, abnormal head growth or shape suggests craniosynostosis 6
• Developmental delays: May indicate underlying neuromuscular or genetic conditions 6

Medication and Treatment History

• Current medications: Phosphate supplements, vitamin D, or other treatments for metabolic conditions 6
• Recent antibiotic use: May mask signs of infection 3
• Response to analgesics: High analgesic requirements despite treatment raise concern for serious pathology 2

Critical Pitfalls to Avoid

• Never assume the child can accurately localize symptoms: Young children frequently mislocalize pain, requiring systematic examination of the entire lower extremity 5, 2
• Do not dismiss normal initial findings: Approximately 10-41% of occult fractures only become visible on follow-up radiographs obtained 7-10 days later 1, 5
• Always consider referred pain: Hip pathology commonly presents as knee or thigh pain 5, 2
• Do not overlook bilateral involvement: Metabolic bone disease, neuromuscular disorders, and systemic conditions often affect both legs 6