Disease flare in juvenile rheumatoid arthritis following intestinal infection

A 19-year-old man, with sero-negative polyarticularjuvenile rheumatoid arthritis for 6 years, well controlled onsulfasalazine for 2 years, presented with acute flare up ofarthritis of both knees, both ankles, right wrist and rightshoulder joint of 5-day duration. He was confined to bed dueto severe pain in knees and ankles. One week prior to theonset of this flare, he had suffered from dysentery (8-10 loosestools/day, mixed with blood) for 2 days, was treated withciprofloxacin and metroindazole. There was no skin rash,redness of eyes, oral ulcers or back pain. There was no pasthistory of similar episodes. Examination revealed pallor,hepatomegaly (3 cm below right costal margin), splenomegaly(just palpable), and a tender joint count of 7 and swollen jointcount of 3. Investigations revealed normocytic,normochromic anemia (Hb 7.5 g/dL), raised inflammatoryparameters (erythrocyte sedimentation rate- 56 mm fall in firsthour, C-reactive protein 3.5 mg/dL), platelets 4.5x10