ABSTRACT
Reactive arthritis is defined as a sterile inflammatory arthritis occurring in association with primary infection at a distant site. Arthritis following primary throat infection with Group A beta, haemolytic Streptococci [GA beta S] may apply to this definition, Because of the similarity between the diagnostic criteria for acute rheumatic fever [ARF] and post-streptococcal reactive arthritis [PSRA], the diagnosis and treatment of PSRA are not well defined. To clarify whether PSRA is a separate disease entity? and to evaluate the extent of joint affection by using various clinical, laboratory and radiological tools. Twenty-five patients with arthritis secondary to infection with GA beta S who attended the Outpatient Rheumatology Clinics in Assuit University Hospitals were included in this study. Other forms of reactive arthritis [ReA] were excluded. All patients were submitted to complete medical history and clinical examination. Erythrocytic sedimentation rate [ESR], C-reactive protein [CRP], complete blood count, rheumatoid factor [RF], antinuclear antibodies [ANA], throat swab and Antistreptolysin O Titre [ASOT], have been done to all patients. Electrocardiogram [ECG] and Echocardiogram [ECHO] were performed. Plain radiography, ultrasonography [US] and Magnetic Resonance Imaging [MRI] to both knees and ankles were done to all patients. Twenty-five patients with a mean age +/- standard deviation of 22.40 +/- 7.42 years were selected. The arthritis persisted for up to six months with a latent period from 10 days to 2 weeks. ASOT was positive with a range from 200-800 IU. Culture of throat swab was positive for GA beta S in 72% of cases, in addition to other organisms [staphylococci in 24% and pneumococci in 16% of the patients]. All of the patients had non migratory arthritis of lower limbs, Knees and ankles synovitis with minimal effusion was detected in 36% of the patients by using ultrasound and 32% and 40% by using MRI respectively. Synovitis with marked effusion of the knees and ankles was detected in 36% and 44% of patients respectively by ultrasound and 40% by MRI. Post-streptococcal arthritis is a separate disease entity. The extent of joint affection might be evaluated by the use of US and MRI as the findings were concordant in knee joint affection. MRI was preferable in evaluating ankle joint synovitis