What is the best course of treatment for migratory swelling affecting multiple joints, including the foot, knee, and hip?

Migratory Joint Swelling: Diagnostic Approach and Management

Migratory polyarthritis affecting multiple large joints (foot, knee, hip) requires urgent rheumatology referral within 6 weeks and immediate evaluation to exclude acute rheumatic fever, disseminated gonococcal infection, and Lyme disease before initiating treatment. 1

Immediate Diagnostic Priorities

Critical Differential Diagnoses to Exclude First

Acute Rheumatic Fever (ARF) is the most critical diagnosis to consider, as migratory polyarthritis involving large joints (knees, ankles, hips) is a hallmark major manifestation. 1 The arthritis in ARF characteristically:

• Migrates rapidly between large joints over days 1
• Responds dramatically to NSAIDs or salicylates within 24-48 hours 1
• Resolves completely without joint deformity 1
• Requires evidence of preceding streptococcal infection (throat culture, rapid strep test, or elevated anti-streptolysin O titers) 1

Disseminated Gonococcal Infection presents with migratory arthralgias progressing to monoarticular or oligoarticular septic arthritis, often accompanied by fever, chills, and characteristic skin lesions (maculopapular or pustular rash). 2 This diagnosis is particularly important in sexually active patients and requires:

• Joint aspiration with culture on chocolate agar 2
• Immediate IV penicillin G if suspected, as cultures are often negative 2, 3

Lyme Arthritis manifests as migratory monoarticular joint swelling, most commonly affecting the knee, in patients with exposure history to endemic areas. 4 Key features include:

• History of tick exposure or camping in northeastern United States 4
• Preceding fever during summer months 4
• Joint aspiration showing dark yellow synovial fluid 4
• Lyme antigen testing of synovial fluid 4
• Treatment with 3-week course of amoxicillin results in complete resolution 4

Mandatory Initial Workup

All patients with migratory polyarthritis require immediate joint aspiration to exclude septic arthritis before any corticosteroid administration. 3 Never inject corticosteroids into a swollen joint until infection is completely eliminated. 3

Laboratory evaluation must include: 1

• Complete blood count (to exclude leukemia, which can mimic juvenile arthritis with migratory large joint involvement) 5
• ESR and CRP (markedly elevated in ARF and infection) 1
• Antistreptolysin O titer and throat culture (for ARF) 1
• Rheumatoid factor and anti-CCP antibodies 1
• Antinuclear antibodies 1
• Urinalysis and transaminases 1
• Serum lactate dehydrogenase (disproportionately elevated in leukemia) 5

Imaging should begin with plain radiographs of all affected joints to exclude fractures, tumors, and assess for joint effusion or periosteal reaction. 1 In early presentations (<14 days), radiographs may only show soft tissue swelling. 1

Rheumatology Referral Timing

Patients with arthritis affecting more than one joint must be referred to and seen by a rheumatologist within 6 weeks of symptom onset. 1 This timeline is critical because:

• Earlier treatment initiation leads to better outcomes 1
• Delay beyond 6 weeks increases risk of persistent erosive disease 1
• Migratory pattern suggests inflammatory arthritis requiring DMARD therapy 1

Clinical Examination Approach

The "squeeze test" is essential: lateral compression of the metatarsophalangeal joints causing pain suggests inflammatory arthritis involving foot joints. 1

Assess for:

• Joint swelling with associated pain or stiffness (defines arthritis) 1
• Morning stiffness duration >30 minutes (suggests inflammatory process) 1
• Rapid improvement with NSAIDs (characteristic of ARF) 1
• Skin lesions (gonococcal infection, Lyme disease) 2, 4
• Fever pattern (preceding infection, systemic disease) 2, 4

Advanced Imaging When Diagnosis Unclear

If initial radiographs are normal but clinical suspicion remains high: 1

• Ultrasound with power Doppler detects synovitis and guides aspiration 1
• MRI without and with IV contrast is most sensitive for detecting early synovitis and bone marrow edema 1
• Image-guided aspiration is ideal for confirming needle placement and reducing complications 1

Treatment Algorithm Based on Diagnosis

For Acute Rheumatic Fever (if confirmed): 1

• NSAIDs or salicylates for symptomatic relief (expect dramatic response)
• Systemic glucocorticoids if carditis present
• Penicillin prophylaxis to prevent recurrence
• Echocardiography mandatory to assess for carditis

For Disseminated Gonococcal Infection: 2

• IV penicillin G 6 × 10⁶ units/day for 10 days
• Treatment of sexual partners mandatory
• Response to penicillin often confirms diagnosis when cultures negative

For Lyme Arthritis: 4

• Amoxicillin for 3 weeks
• Complete symptom resolution expected

For Early Inflammatory Arthritis (if infectious causes excluded): 1

• NSAIDs after evaluating gastrointestinal, renal, and cardiovascular status 1
• Systemic glucocorticoids as temporary adjunctive treatment 1
• Methotrexate as anchor DMARD if risk factors for persistent disease present 1
• Goal is achieving remission with regular disease activity monitoring 1

Critical Pitfalls to Avoid

Never delay infectious workup: Patients with preexisting joint disease, immunosuppression, or malignancy are at highest risk for septic arthritis. 3 Infection must be the first consideration in these populations. 3

Beware of leukemia masquerading as arthritis: Migratory arthritis with disproportionately elevated acute phase reactants, markedly elevated LDH, and night pain should prompt immediate hematologic evaluation. 5 Characteristic radiological bone changes may be present. 5

Do not assume rheumatoid arthritis: The migratory pattern described is atypical for RA, which characteristically involves small joints symmetrically rather than large joints in a migratory fashion. 6 The hip, knee, and foot pattern with migration strongly suggests ARF, infection, or reactive arthritis rather than RA. 1, 2, 4