Background: Renal manifestations are rare in Kawasaki disease (KD). Acute renal failure with tubular necrosis, tubulointerstitial nephritis and renovascular hypertension have been reported in KD, but only one case of a patient with KD associated with nephrotic syndrome (NS) has been reported to date, with the patient improving on steroid therapy but dying from coronary aneurysm.
Methods: We report the cases of three children, aged 4, 4.5 and 8 years, respectively, who presented with typical KD symptoms (high fever, diffuse maculopapular rash, conjunctivitis, peripheral oedema, cervical adenopathies and high C reactive protein levels) and developed NS.
Results: Patient 1 had a haemodynamic shock due to cardiac dysfunction and transient renal failure. Ten days later, he developed a NS which spontaneously disappeared 1 week later. Patient 2 had a NS on admission with normal plasma creatinine and no haematuria. Proteinuria disappeared within 10 days. Patient 3 developed NS 5 days after onset with a moderate increase in plasma creatinine. Proteinuria disappeared within 2 weeks. All three patients were treated with intravenous immunoglobulins, antibiotic therapy and aspirin, but none of them received steroid therapy. To date, all three patients have maintained long-term remission.
Conclusions: In conclusion, proteinuria with NS may develop during the acute phase of KD with persistent remission occurring without steroid therapy.