Limping Child

“The Limping Child” Pediatric Rheumatology Case

Thomas, 2 year old male o o o o

4 months history of limping with left knee swelling Associated with morning stiffness No fever or rash No history of trauma or antecedent infection

Musculoskeletal Examination • •

Limping gait Swelling of the left knee with warmth (no erythema/tenderness)

•

Unable to fully flex or extend the left knee

Laboratory Tests Findings CBC Hgb 12 Hct 0.38 WBC 8,600 polys 45% lymphs 47% monos 8% Platelets 250,000

ESR 20 mm/hr Rheumatoid factor (-) ANA (+) 1:640 titer ASO titer <200

QUESTION #1 Give the salient features of the patient.

Salient Features A 2 year old male with chronic (> 6 weeks) monoarthritis (inflammation of the left knee) with morning stiffness.

QUESTION #2 What is the most likely diagnosis of the patient?

JUVENILE RHEUMATOID ARTHRITIS PAUCIARTICULAR TYPE

ACR Criteria for JRA Age of onset < 16 years of age o Persistent arthritis in at least one joint for > 6 weeks o Exclusion of other diagnoses o

Types of JRA •

PAUCIARTICULAR ( < 5 joints) • POLYARTICULAR (>/= 5 joints) • SYSTEMIC (1 or more joints + fever/rash)

QUESTION #3 Give the differential diagnosis of the patient.

Septic Arthritis •

Usually presents as monoarthritis • Large joints of the lower extremity (most common sites of infection) • Accompanied by systemic signs of illness (e.g. Fever, headaches, chills, vomiting) • Very severe joint pain with red, hot, swollen joint on examination

Reactive Arthritis • • • • • •

Occurs after a history of infection Affects both large and small joints +/- systemic symptoms of illness Affected joints are swollen +/warmth/tenderness, (-) erytheaa Self-limiting course (rarely lasting for > 6 weeks) Good response with NSAIDs

Acute Rheumatic Fever • • •

Occurs following a Grp A Streptococcal infection Peak age 6-15 years old Jones criteria MAJOR

MINOR

-Carditis -Arthritis -Sydenham’s chorea -Erythema marginatum -Subcutaneous nodules

-Fever -Arthralgia -Elevated ESR/CRP -Prolonged PR interval

Supporting evidence of antecedent Group A                     Streptococcal infection

Acute Rheumatic Fever •

Arthritis of RF affects primarily large joints • Migratory in nature (joint symptom resolving spontaneously within hours, only to reappear to another joint) • Very severe joint pain (may cause pseudoparalysis) • Joint symptom very responsive to Aspirin

Juvenile Spondyloarthropathy • • • • •

Common in adolescent males Usually presents as chronic asymmetric arthritis Large joints are commonly affected (+) axial involvement (back pain is a common symptom) Associated with HLA-B27

Hemarthroses •

Bleeding inside the joint • Occurs following an injury • Spontaneous bleeding in patients with coagulation disorder (e.g. Hemophilia) • Affected joint is warm, very painful, swollen with limited range of motion.

QUESTION #4 What is the implication of a positive ANA in a patient with JRA?

ANA in JRA ANA positivity is a knowm risk factor for the occurrence of chronic uveitis. Regular ophthalmologic evaluation is advised until 7 years from the onset of disease.

QUESTION #5 Is Rheumatoid Factor specific for JRA?

Rheumatoid Factor •

Not specific for JRA • Can be positive in certain infections and malignancies • Only 10-15% of JRA patients are positive for Rheumatoid factor JRA patients with (+) RF have a more aggressive disease          with poorer overall functional outcome.

QUESTION #6 What is the most appropriate treatment for this child?

Treatment plan • • • •

Medications: NSAIDs (e.g. Ibuprofen, Naproxen) Intraarticular steroid injection Physical therapy for stretching and range of motion exercises Regular ophthalmologic evaluation

NO ROLE FOR DMARDs IN PAUCIARTICULAR JRA