What is the appropriate diagnosis and treatment for an 18-year-old patient presenting with right toe pain, swelling, and warmth to touch?

Right Toe Pain, Swollen, and Warm in an 18-Year-Old

The most critical first step is to determine if this represents an infection by assessing for at least two classic inflammatory signs (erythema, warmth, tenderness, pain, swelling) or purulent discharge, as infection carries the highest morbidity and mortality risk. 1

Immediate Assessment: Rule Out Infection First

Diagnose infection clinically if at least 2 of the following are present: 1

• Local swelling or induration
• Erythema >0.5 cm around any wound (if present)
• Local tenderness or pain
• Local warmth
• Purulent discharge

If infection is confirmed (≥2 signs present): 1

• Classify severity immediately: mild (erythema <2 cm, superficial), moderate (erythema ≥2 cm or deeper tissue involvement), or severe (systemic signs present)
• Check for systemic inflammatory response: temperature >38°C or <36°C, heart rate >90 bpm, respiratory rate >20 breaths/min, WBC >12,000 or <4,000/mm³ 1
• Obtain wound cultures if any break in skin is present 1
• Initiate antibiotics immediately for confirmed infection 1
• Consider plain radiographs to evaluate for osteomyelitis 1

If No Open Wound or Infection: Consider Trauma and Inflammatory Causes

Obtain detailed history focusing on: 2

• Mechanism of injury (inversion trauma, direct blow, repetitive stress)
• Timing of symptom onset (acute vs. gradual)
• Recent increase in activity or change in walking surface 3
• Ability to bear weight immediately after onset 3

Physical examination must localize the pain precisely: 3, 2

• Palpate each toe joint individually for point tenderness
• Assess for tenderness over the metatarsal heads and shafts
• Perform calcaneal squeeze test (medial-to-lateral compression) if pain extends to hindfoot 3
• Test active and passive range of motion of each toe joint
• Examine for deformity, ecchymosis, or instability

Imaging Based on Ottawa Ankle Rules

Obtain plain radiographs if: 3

• Unable to bear weight immediately after injury
• Unable to take 4 steps
• Point tenderness over any bone
• Visible deformity present

If initial radiographs are negative but pain persists >1 week: 3

• MRI without contrast or CT without contrast are equivalent alternatives
• Consider technetium bone scan for suspected stress fracture, as symptoms often precede radiographic findings 3

Differential Diagnosis for Isolated Toe Pain with Warmth and Swelling

Acute traumatic causes: 4

• Toe fracture (phalangeal or metatarsal head/neck)
• Toe dislocation
• Acute ligamentous injury

Inflammatory arthropathy (especially if bilateral or other joint involvement): 5

• Gout (most common in first metatarsophalangeal joint in young adults)
• Reactive arthritis
• Early rheumatoid arthritis (though typically affects metatarsophalangeal joints symmetrically)

Stress-related injury: 3

• Metatarsal stress fracture (progressive pain with increased activity)
• Positive calcaneal squeeze test suggests stress fracture

Critical Pitfalls to Avoid

Never dismiss infection possibility: 1

• Even without visible wound, infection can occur through minor breaks in skin
• Warmth + swelling + tenderness = infection until proven otherwise in at-risk patients

Do not rely solely on initial radiographs: 3

• Sensitivity for stress fractures is only 12-56%
• Reexamine at 3-5 days if initial swelling limits examination

Consider septic arthritis in the differential: 1

• Requires urgent joint aspiration if suspected
• Presents with severe pain, warmth, swelling, and inability to move the joint

Assess for systemic inflammatory conditions: 5

• Check for involvement of other joints
• Morning stiffness >1 hour suggests inflammatory arthritis
• Consider ESR, CRP, and uric acid levels if inflammatory arthritis suspected

Initial Management Approach

For confirmed non-infectious causes: 3, 4

• Rest and activity modification
• Ice application
• Elevation
• NSAIDs for pain and inflammation
• Protected weight-bearing or buddy taping as appropriate
• Follow-up in 3-5 days to reassess

Refer immediately if: 3

• Infection confirmed or suspected
• Fracture or dislocation identified
• Severe pain with inability to bear weight
• No improvement after 1 week of conservative treatment