How should I evaluate and treat a 10‑to‑19‑year‑old adolescent presenting with foot swelling without any specific history?

Evaluation and Management of Adolescent Foot Swelling

Begin with plain radiographs of the foot (AP, oblique, lateral views) to exclude fracture, bone destruction, or foreign bodies, then proceed with a focused clinical examination to differentiate between the most common causes: calcaneal apophysitis (Sever's disease), trauma, infection, or less commonly tarsal coalition or osteochondrosis. 1

Initial Diagnostic Approach

Immediate Clinical Assessment

Determine the location and character of swelling:

• Posterior heel swelling with activity-related pain strongly suggests calcaneal apophysitis, the most common cause of adolescent heel pain, typically occurring during the pubertal growth spurt (mean age 10, range 7-15 years) 2, 3
• Diffuse foot swelling with erythema, warmth, tenderness, or purulent discharge requires evaluation for infection, which needs at least two of these inflammatory signs for diagnosis 2, 1
• Unilateral swelling without skin changes should prompt consideration of deep vein thrombosis if there is recent trauma, immobilization, or surgery 1, 4

Key History Elements to Elicit

• Recent increase in athletic activity, particularly running or jumping sports, points toward overuse syndromes like calcaneal apophysitis 3, 5
• History of trauma or fall from height suggests calcaneal fracture, which requires radiographic confirmation 2
• Night pain or absence of precipitating activity in unilateral cases raises concern for rare tumors and warrants further investigation 3
• Diabetes history necessitates evaluation for diabetic foot complications, though these are rare in adolescents 2

Physical Examination Findings

Palpate specific anatomical structures:

• Tenderness on lateral calcaneal wall compression is highly suspicious for stress fracture 2
• Posterior heel tenderness at the calcaneal apophysis with pain on squeeze test confirms Sever's disease 3, 5
• Midfoot or forefoot swelling may indicate Freiberg's infarction (metatarsal head necrosis) or Köhler's disease (navicular necrosis), though these are less common 5, 6
• Rigid flatfoot deformity suggests tarsal coalition, which can present with pain and swelling 5, 6

Imaging Strategy

First-Line Imaging

Obtain three-view radiographs (AP, oblique, lateral) of the affected foot in all cases to evaluate for fractures, dislocations, bone destruction, or foreign bodies 1. Note that radiographs may be normal in early stress fractures and calcaneal apophysitis 2, 3.

Advanced Imaging Indications

• Technetium bone scan if stress fracture is suspected clinically but radiographs are negative 2
• MRI is indicated when diagnosis remains unclear after plain films, particularly for suspected osteomyelitis, deep soft tissue infection, or avascular necrosis 7, 1
• Ultrasound duplex Doppler if deep vein thrombosis is suspected based on unilateral swelling with risk factors 1, 4

Management Based on Diagnosis

Calcaneal Apophysitis (Sever's Disease)

This is a self-limiting condition that resolves at skeletal maturity and requires only palliative treatment 2:

• Reduce athletic activity intensity
• Soft heel cushioning in shoes
• Weight reduction if obesity is present
• Reassure patient and family about benign, self-resolving nature 5

Traumatic Injuries

• Acute calcaneal fractures require surgical consultation for intra-articular or displaced fractures 2
• Stress fractures need protection and immobilization of the foot 2
• Simple, non-articular, minimally displaced fractures can be managed with immobilization alone 2

Infection

If at least two inflammatory signs are present (swelling, erythema >0.5 cm, tenderness, warmth, purulent discharge), treat as infection 2:

• Initiate empiric antibiotics if infection cannot be excluded
• Consider blood cultures if systemically ill
• Obtain wound cultures if ulceration present
• Urgent surgical consultation if deep-space infection or abscess suspected 1

Avascular Necrosis (Osteochondroses)

Freiberg's disease (metatarsal head) and Köhler's disease (navicular) are always managed conservatively with activity modification and protected weight-bearing 5.

Red Flags Requiring Urgent Referral

• Night pain or constitutional symptoms suggesting possible malignancy 3
• Localized swelling with bony expansion concerning for tumor 3
• Suspected deep vein thrombosis requires immediate ultrasound and potential anticoagulation 4
• Signs of systemic inflammatory response (fever, tachycardia, elevated WBC) indicating severe infection 2
• Neurologic symptoms warrant subspecialist evaluation for nerve impingement 2

Common Pitfalls to Avoid

• Do not assume absence of radiographic findings excludes significant pathology—stress fractures and early apophysitis may have normal X-rays initially 2, 3
• Do not dismiss unilateral presentation as benign—atypical features warrant investigation for rare but serious conditions 3
• Do not overlook footwear assessment—ill-fitting shoes are a frequent cause of adolescent foot pathology 1
• In diabetic adolescents, do not assume minimal pain excludes serious pathology—neuropathy may mask infection or Charcot arthropathy 1