A patient with juvenile chronic arthritis and Henoch-Schönlein purpura

Abstract

A 21-year-old woman was ®rst referred to a rheumatologist (HAC) when aged 14 years. She had developed progressive joint discomfort and was diagnosed as having juvenile chronic arthritis (rheumatoid-factor-negative polyarticular arthritis). 1She had previously required several steroid injections and had been on sulphasalazine, hydroxychloroquine, gold and methotrexate; on this admission she remained on hydroxychloroquine. Two weeks before this admission, she had been given steroid injections into her metacarpophalangeal and proximal interphalangeal joints but continued to complain of increasing pain and stiffness in her hands, wrists and knees. Her left wrist and left knee were aspirated and there was no growth on culture. She was therefore admitted (day 0) and received steroid injections into both knees with a good symptomatic response. Shortly after admission, she developed a vasculitic rash on her legs which spread to her buttocks and forearms.On day 1, her C-reactive protein (CRP) was 115 mg/L (reference range 10) and the erythrocyte sedimentation rate was 71 mm/h (reference range 12). Investigations showed that she was negative for anti-nuclear antibody (ANA) and rheumatoid factor (RF), with normal complement C3 and reduced complement C4. Serum cryoglobulins were negative. Serum immunoglobulin IgG was 15´8 g/L (reference range 6±15); IgA and IgM concentrations were within reference ranges. Albumin excretion was 1´9 mg/mmol creatinine.Her rash began to fade and her CRP fell to 15 mg/L on day 5 without intervention; she was therefore discharged on day 6. However, shortly after discharge, the rash intensi®ed and was consistent with Henoch±SchoÈ nlein purpura. When she was seen as an out-patient on day 10, her CRP was 48 mg/L. ANA, RF and C3 remained normal and C4 was reduced; these did not change throughout this study. On days 12 and 14, screens for pANCA (perinuclear antibodies to neutrophil cytoplasmic antibodies) were weakly positive at 1/40. A con®rmatory test on formalin-®xed neutrophils was inconclusive, but ethanol-®xed neutrophils identi®ed pANCA. Screens for cytoplasmic antibodies to neutrophil cytoplasmic antibodies (cANCA) were negative. No further requests were made for pANCA or cANCA.She was re-admitted on day 13. On examination, her skin was seen to have broken down over the dorsum of her feet and she had developed a vasculitic ulcer on her left foot. This became infected and swabs grew a Proteus species. CRP rose to 83 mg/L on day 17. She was treated with appropriate dressings and intravenous antibiotics (amoxycillin and clavulanic acid on days 15±19, and amoxycillin and gentamicin on days 26±33). Oral¯ucloxacillin was given from day 33 to day 39. A skin biopsy demonstrated a leucocytoclastic vasculitis. She was started on steroids (methylprednisolone, 40 mg on alternate days) and an immunosuppressant (azathioprine, 50 mg/day, which was increased to 75 mg/day from day 27 and to 100 mg/day from day 34). CRP fell on therapy, but¯uctuated and remained elevated.Creatinine clearance was requested beca...