Swollen Middle Finger Without Trauma
For a swollen middle finger without trauma, obtain plain radiographs first to rule out fracture or bony pathology, then consider ultrasound or MRI to evaluate for soft tissue causes such as tenosynovitis, inflammatory arthritis, infection, or rare conditions like intrinsic muscle contracture.
Initial Diagnostic Approach
Imaging Studies
- Plain radiographs are always indicated as the initial imaging study for any hand complaint, even without trauma history, to detect occult fractures, foreign bodies, arthritis, or bony lesions 1, 2.
- Standard three-view radiographs (anteroposterior, lateral, and oblique) should be obtained to identify any bony abnormalities 3.
- In rare cases, a swollen finger may represent the first manifestation of malignancy with acrometastasis, which appears as a lytic lesion on radiographs 4.
Advanced Imaging When Radiographs Are Normal or Nonspecific
- Ultrasound is the next appropriate step when radiographs are normal or show only nonspecific findings, as it can identify synovitis, joint effusion, tenosynovitis, tendinopathy, and soft tissue pathology 1.
- The American College of Rheumatology supports ultrasound use in patients presenting with pain and swelling without definitive diagnosis 1.
- MRI without IV contrast is the preferred advanced imaging if ultrasound is inconclusive or unavailable, particularly for evaluating tendon injuries, nerve compression, and soft tissue abnormalities 1, 5.
- MRI changed clinical management in 69.5% of hand/wrist cases in one study and was particularly useful in reassuring patients when no pathology was found 1.
Differential Diagnosis to Consider
Inflammatory and Infectious Causes
- Septic arthritis or tenosynovitis must be excluded, especially if there is warmth, erythema, or systemic symptoms 1.
- Inflammatory arthritis including erosive osteoarthritis can present with isolated finger swelling 1.
- Look for signs of paronychia or chronic candidal infection if there is occupational water exposure 1.
Vascular and Rare Conditions
- Acute blue finger syndrome is a rare benign condition that mimics digital ischemia, presenting with blue discoloration, pain, and swelling that resolves spontaneously within 48 hours 6.
- Intrinsic plus hand is a rare painful contracture causing finger swelling and contracture, requiring evaluation for cerebrovascular injury, infection, compartment syndrome, or deep vein thrombosis 7.
Neoplastic Causes
- Acrometastasis should be considered in patients with cancer history or unexplained lytic lesions, as 16% of hand metastases are the first manifestation of malignancy 4.
Treatment Based on Diagnosis
Conservative Management
- Elevation of the swollen finger accelerates healing and should be accomplished using a sling or passive method 1.
- Remove any jewelry or constricting materials immediately to prevent vascular compromise 1.
- Apply ice and consider NSAIDs for pain and inflammation if no contraindications exist 1.
Specific Interventions
- For inflammatory arthritis: Topical or intra-articular corticosteroids may provide short-term relief, though evidence for interphalangeal joints is limited 1.
- For infection: Prompt antibiotic therapy and possible surgical drainage if abscess or septic arthritis is confirmed 1.
- For trigger finger or tenosynovitis: Splinting and corticosteroid injection may be considered 8.
Red Flags Requiring Urgent Evaluation
- Pain disproportionate to examination findings suggests possible compartment syndrome, septic arthritis, or osteomyelitis 1.
- Inability to actively move the finger or severe pain with passive motion warrants immediate orthopedic consultation 7.
- Systemic symptoms (fever, malaise) suggest infection requiring urgent treatment 1.
- Progressive symptoms despite conservative management within 24 hours necessitate re-evaluation 1.